642624661 has 12 divisors (see below), whose sum is σ = 752928960. Its totient is φ = 546852600.

The previous prime is 642624649. The next prime is 642624673. The reversal of 642624661 is 166426246.

642624661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (642624649) and next prime (642624673).

It is not a de Polignac number, because 642624661 - 2⁹ = 642624149 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642624661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642624161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40365 + ... + 53986.

It is an arithmetic number, because the mean of its divisors is an integer number (62744080).

Almost surely, 2^642624661 is an apocalyptic number.

It is an amenable number.

642624661 is a deficient number, since it is larger than the sum of its proper divisors (110304299).

642624661 is a wasteful number, since it uses less digits than its factorization.

642624661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94504 (or 94497 counting only the distinct ones).

The product of its digits is 82944, while the sum is 37.

The square root of 642624661 is about 25350.0426232383. The cubic root of 642624661 is about 862.9503235729.

The spelling of 642624661 in words is "six hundred forty-two million, six hundred twenty-four thousand, six hundred sixty-one".