15978224025 has 75 divisors (see below), whose sum is σ = 30166370971. Its totient is φ = 8360932320.

The previous prime is 15978223951. The next prime is 15978224051. The reversal of 15978224025 is 52042287951.

The square root of 15978224025 is 126405.

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

15978224025 is a `hidden beast` number, since 159 + 78 + 22 + 402 + 5 = 666.

It can be written as a sum of positive squares in 7 ways, for example, as 3273327369 + 12704896656 = 57213^2 + 112716^2 .

It is a tau number, because it is divible by the number of its divisors (75).

It is a de Polignac number, because none of the positive numbers 2^k-15978224025 is a prime.

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

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 301475899 + ... + 301475951.

Almost surely, 2^15978224025 is an apocalyptic number.

15978224025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

15978224025 is the 126405-th square number.

15978224025 is the 63203-rd centered octagonal number.

It is an amenable number.

15978224025 is a deficient number, since it is larger than the sum of its proper divisors (14188146946).

15978224025 is an frugal number, since it uses more digits than its factorization.

15978224025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 15978224025 in words is "fifteen billion, nine hundred seventy-eight million, two hundred twenty-four thousand, twenty-five".