642612851 has 10 divisors (see below), whose sum is σ = 678450852. Its totient is φ = 608667660.

The previous prime is 642612833. The next prime is 642612871. The reversal of 642612851 is 158216246.

It is not a de Polignac number, because 642612851 - 2²⁶ = 575503987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642612871) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 127856 + ... + 132786.

Almost surely, 2^642612851 is an apocalyptic number.

642612851 is a deficient number, since it is larger than the sum of its proper divisors (35838001).

642612851 is an frugal number, since it uses more digits than its factorization.

642612851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5007 (or 4950 counting only the distinct ones).

The product of its digits is 23040, while the sum is 35.

The square root of 642612851 is about 25349.8096837037. The cubic root of 642612851 is about 862.9450371766.

It can be divided in two parts, 6426 and 12851, that multiplied together give a triangular number (82580526 = T₁₂₈₅₁).

The spelling of 642612851 in words is "six hundred forty-two million, six hundred twelve thousand, eight hundred fifty-one".