642751047621 has 48 divisors (see below), whose sum is σ = 951608466432. Its totient is φ = 417897916800.

The previous prime is 642751047613. The next prime is 642751047683. The reversal of 642751047621 is 126740157246.

642751047621 is a `hidden beast` number, since 6 + 4 + 2 + 7 + 5 + 10 + 4 + 7 + 621 = 666.

It is not a de Polignac number, because 642751047621 - 2³ = 642751047613 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642751049621) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 216924286 + ... + 216927248.

It is an arithmetic number, because the mean of its divisors is an integer number (19825176384).

Almost surely, 2^642751047621 is an apocalyptic number.

It is an amenable number.

642751047621 is a deficient number, since it is larger than the sum of its proper divisors (308857418811).

642751047621 is a wasteful number, since it uses less digits than its factorization.

642751047621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5594 (or 5591 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The spelling of 642751047621 in words is "six hundred forty-two billion, seven hundred fifty-one million, forty-seven thousand, six hundred twenty-one".