780121730025 has 243 divisors, whose sum is σ = 1581035912911. Its totient is φ = 367429920000.

The previous prime is 780121729987. The next prime is 780121730051. The reversal of 780121730025 is 520037121087.

The square root of 780121730025 is 883245.

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

It can be written as a sum of positive squares in 13 ways, for example, as 9820611801 + 770301118224 = 99099^2 + 877668^2 .

It is a de Polignac number, because none of the positive numbers 2^k-780121730025 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 7723977475 + ... + 7723977575.

Almost surely, 2^780121730025 is an apocalyptic number.

780121730025 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

780121730025 is the 883245-th square number.

780121730025 is the 441623-rd centered octagonal number.

It is an amenable number.

780121730025 is an abundant number, since it is smaller than the sum of its proper divisors (800914182886).

780121730025 is a wasteful number, since it uses less digits than its factorization.

780121730025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 36.

Multiplying 780121730025 by its sum of digits (36), we get a square (28084382280900 = 5299470²).

The spelling of 780121730025 in words is "seven hundred eighty billion, one hundred twenty-one million, seven hundred thirty thousand, twenty-five".