642622051 has 4 divisors (see below), whose sum is σ = 643376272. Its totient is φ = 641867832.

The previous prime is 642622037. The next prime is 642622067. The reversal of 642622051 is 150226246.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642622051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642622091) 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, 375831 + ... + 377536.

It is an arithmetic number, because the mean of its divisors is an integer number (160844068).

Almost surely, 2^642622051 is an apocalyptic number.

642622051 is a deficient number, since it is larger than the sum of its proper divisors (754221).

642622051 is an equidigital number, since it uses as much as digits as its factorization.

642622051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 754220.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 642622051 is about 25349.9911439827. The cubic root of 642622051 is about 862.9491552894.

Adding to 642622051 its reverse (150226246), we get a palindrome (792848297).

The spelling of 642622051 in words is "six hundred forty-two million, six hundred twenty-two thousand, fifty-one".