642512901 has 4 divisors (see below), whose sum is σ = 856683872. Its totient is φ = 428341932.

The previous prime is 642512887. The next prime is 642512917. The reversal of 642512901 is 109215246.

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 not a de Polignac number, because 642512901 - 2⁵ = 642512869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642510901) 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, 107085481 + ... + 107085486.

It is an arithmetic number, because the mean of its divisors is an integer number (214170968).

Almost surely, 2^642512901 is an apocalyptic number.

It is an amenable number.

642512901 is a deficient number, since it is larger than the sum of its proper divisors (214170971).

642512901 is a wasteful number, since it uses less digits than its factorization.

642512901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214170970.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 642512901 is about 25347.8381918459. The cubic root of 642512901 is about 862.9002949297.

The spelling of 642512901 in words is "six hundred forty-two million, five hundred twelve thousand, nine hundred one".