1281998025 has 243 divisors, whose sum is σ = 3033756999. Its totient is φ = 515592000.

The previous prime is 1281997987. The next prime is 1281998027. The reversal of 1281998025 is 5208991821.

The square root of 1281998025 is 35805.

It is a perfect power (a square), and thus also a powerful number.

1281998025 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 461519289 + 820478736 = 21483^2 + 28644^2 .

It is not a de Polignac number, because 1281998025 - 2¹¹ = 1281995977 is a prime.

It is a super-2 number, since 2×1281998025² = 3287037872207801250, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1281998027) by changing a digit.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 41354760 + ... + 41354790.

Almost surely, 2^1281998025 is an apocalyptic number.

1281998025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1281998025 is the 35805-th square number.

1281998025 is the 17903-rd centered octagonal number.

It is an amenable number.

1281998025 is an abundant number, since it is smaller than the sum of its proper divisors (1751758974).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1281998025 is a wasteful number, since it uses less digits than its factorization.

1281998025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The cubic root of 1281998025 is about 1086.3316981761.

The spelling of 1281998025 in words is "one billion, two hundred eighty-one million, nine hundred ninety-eight thousand, twenty-five".