21446138025 has 81 divisors (see below), whose sum is σ = 41649968997. Its totient is φ = 10544040000.

The previous prime is 21446138011. The next prime is 21446138039. The reversal of 21446138025 is 52083164412.

It is a happy number.

The square root of 21446138025 is 146445.

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

21446138025 is a `hidden beast` number, since 2 + 14 + 4 + 613 + 8 + 0 + 25 = 666.

It is an interprime number because it is at equal distance from previous prime (21446138011) and next prime (21446138039).

It can be written as a sum of positive squares in 4 ways, for example, as 5527773801 + 15918364224 = 74349^2 + 126168^2 .

It is not a de Polignac number, because 21446138025 - 2⁷ = 21446137897 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 28556400 + ... + 28557150.

Almost surely, 2^21446138025 is an apocalyptic number.

21446138025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21446138025 is the 146445-th square number.

21446138025 is the 73223-rd centered octagonal number.

It is an amenable number.

21446138025 is a deficient number, since it is larger than the sum of its proper divisors (20203830972).

21446138025 is an equidigital number, since it uses as much as digits as its factorization.

21446138025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1544 (or 772 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

Multiplying 21446138025 by its sum of digits (36), we get a square (772060968900 = 878670²).

The spelling of 21446138025 in words is "twenty-one billion, four hundred forty-six million, one hundred thirty-eight thousand, twenty-five".