645487748742 has 16 divisors (see below), whose sum is σ = 1320998184000. Its totient is φ = 210158801832.

The previous prime is 645487748677. The next prime is 645487748797. The reversal of 645487748742 is 247847784546.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1250944992 + ... + 1250945507.

It is an arithmetic number, because the mean of its divisors is an integer number (82562386500).

Almost surely, 2^645487748742 is an apocalyptic number.

645487748742 is an abundant number, since it is smaller than the sum of its proper divisors (675510435258).

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

645487748742 is a wasteful number, since it uses less digits than its factorization.

645487748742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2501890547.

The product of its digits is 337182720, while the sum is 66.

The spelling of 645487748742 in words is "six hundred forty-five billion, four hundred eighty-seven million, seven hundred forty-eight thousand, seven hundred forty-two".