21742977025 has 81 divisors (see below), whose sum is σ = 34563772803. Its totient is φ = 13518674400.

The previous prime is 21742977001. The next prime is 21742977029. The reversal of 21742977025 is 52077924712.

The square root of 21742977025 is 147455.

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

It can be written as a sum of positive squares in only one way, i.e., 7827471729 + 13915505296 = 88473^2 + 117964^2 .

It is not a de Polignac number, because 21742977025 - 2¹⁷ = 21742845953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21742977029) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 56769984 + ... + 56770366.

Almost surely, 2^21742977025 is an apocalyptic number.

21742977025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21742977025 is the 147455-th square number.

21742977025 is the 73728-th centered octagonal number.

It is an amenable number.

21742977025 is a deficient number, since it is larger than the sum of its proper divisors (12820795778).

21742977025 is an equidigital number, since it uses as much as digits as its factorization.

21742977025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 812 (or 406 counting only the distinct ones).

The product of its (nonzero) digits is 493920, while the sum is 46.

The spelling of 21742977025 in words is "twenty-one billion, seven hundred forty-two million, nine hundred seventy-seven thousand, twenty-five".