642249951 has 32 divisors (see below), whose sum is σ = 1032345600. Its totient is φ = 346952160.

The previous prime is 642249941. The next prime is 642249991. The reversal of 642249951 is 159942246.

It is not a de Polignac number, because 642249951 - 2¹⁴ = 642233567 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642249911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 226420 + ... + 229238.

It is an arithmetic number, because the mean of its divisors is an integer number (32260800).

Almost surely, 2^642249951 is an apocalyptic number.

642249951 is a deficient number, since it is larger than the sum of its proper divisors (390095649).

642249951 is a wasteful number, since it uses less digits than its factorization.

642249951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3419.

The product of its digits is 155520, while the sum is 42.

The square root of 642249951 is about 25342.6508281987. The cubic root of 642249951 is about 862.7825641716.

The spelling of 642249951 in words is "six hundred forty-two million, two hundred forty-nine thousand, nine hundred fifty-one".