642978001 has 4 divisors (see below), whose sum is σ = 656658432. Its totient is φ = 629297572.

The previous prime is 642977989. The next prime is 642978043. The reversal of 642978001 is 100879246.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 642978001 - 2⁵ = 642977969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (642970001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6840145 + ... + 6840238.

It is an arithmetic number, because the mean of its divisors is an integer number (164164608).

Almost surely, 2^642978001 is an apocalyptic number.

It is an amenable number.

642978001 is a deficient number, since it is larger than the sum of its proper divisors (13680431).

642978001 is a wasteful number, since it uses less digits than its factorization.

642978001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13680430.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 642978001 is about 25357.0108845660. The cubic root of 642978001 is about 863.1084557964.

The spelling of 642978001 in words is "six hundred forty-two million, nine hundred seventy-eight thousand, one".