669257551872 has 832 divisors, whose sum is σ = 2473435614720. Its totient is φ = 176292495360.

The previous prime is 669257551871. The next prime is 669257551909. The reversal of 669257551872 is 278155752966.

669257551872 is a `hidden beast` number, since 6 + 6 + 9 + 2 + 5 + 7 + 551 + 8 + 72 = 666.

It is a tau number, because it is divible by the number of its divisors (832).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669257551871) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 815173222 + ... + 815174042.

Almost surely, 2^669257551872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669257551872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1236717807360).

669257551872 is an abundant number, since it is smaller than the sum of its proper divisors (1804178062848).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

669257551872 is an frugal number, since it uses more digits than its factorization.

669257551872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 886 (or 846 counting only the distinct ones).

The product of its digits is 63504000, while the sum is 63.

The spelling of 669257551872 in words is "six hundred sixty-nine billion, two hundred fifty-seven million, five hundred fifty-one thousand, eight hundred seventy-two".