669704906025 has 81 divisors (see below), whose sum is σ = 1215127297839. Its totient is φ = 352586615040.

The previous prime is 669704906023. The next prime is 669704906083. The reversal of 669704906025 is 520609407966.

The square root of 669704906025 is 818355.

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

669704906025 is a `hidden beast` number, since 6 + 6 + 9 + 70 + 490 + 60 + 25 = 666.

It can be written as a sum of positive squares in 13 ways, for example, as 560059153641 + 109645752384 = 748371^2 + 331128^2 .

It is not a de Polignac number, because 669704906025 - 2¹ = 669704906023 is a prime.

It is a super-2 number, since 2×669704906025² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (669704906023) 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, 1092503619 + ... + 1092504231.

Almost surely, 2^669704906025 is an apocalyptic number.

669704906025 is the 818355-th square number.

669704906025 is the 409178-th centered octagonal number.

It is an amenable number.

669704906025 is a deficient number, since it is larger than the sum of its proper divisors (545422391814).

669704906025 is an frugal number, since it uses more digits than its factorization.

669704906025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1420 (or 710 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 54.

The spelling of 669704906025 in words is "six hundred sixty-nine billion, seven hundred four million, nine hundred six thousand, twenty-five".