645157387776 has 160 divisors (see below), whose sum is σ = 1875687948288. Its totient is φ = 195429335040.

The previous prime is 645157387727. The next prime is 645157387789. The reversal of 645157387776 is 677783751546.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

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, 60533040 + ... + 60543696.

Almost surely, 2^645157387776 is an apocalyptic number.

645157387776 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645157387776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (937843974144).

645157387776 is an abundant number, since it is smaller than the sum of its proper divisors (1230530560512).

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

645157387776 is a wasteful number, since it uses less digits than its factorization.

645157387776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14272 (or 14256 counting only the distinct ones).

The product of its digits is 207446400, while the sum is 66.

The spelling of 645157387776 in words is "six hundred forty-five billion, one hundred fifty-seven million, three hundred eighty-seven thousand, seven hundred seventy-six".