669297128640 has 112 divisors (see below), whose sum is σ = 2428592462592. Its totient is φ = 152982199296.

The previous prime is 669297128639. The next prime is 669297128659. The reversal of 669297128640 is 46821792966.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (60).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49792174 + ... + 49805613.

Almost surely, 2^669297128640 is an apocalyptic number.

669297128640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

669297128640 is an abundant number, since it is smaller than the sum of its proper divisors (1759295333952).

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

669297128640 is a wasteful number, since it uses less digits than its factorization.

669297128640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99597814 (or 99597804 counting only the distinct ones).

The product of its (nonzero) digits is 15676416, while the sum is 60.

It can be divided in two parts, 6692971 and 28640, that added together give a triangular number (6721611 = T₃₆₆₆).

The spelling of 669297128640 in words is "six hundred sixty-nine billion, two hundred ninety-seven million, one hundred twenty-eight thousand, six hundred forty".