642476551 has 4 divisors (see below), whose sum is σ = 644542704. Its totient is φ = 640410400.

The previous prime is 642476537. The next prime is 642476557. The reversal of 642476551 is 155674246.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 642476551 - 2⁹ = 642476039 is a prime.

It is a super-2 number, since 2×642476551² = 825552237169711202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642476557) 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, 1032610 + ... + 1033231.

It is an arithmetic number, because the mean of its divisors is an integer number (161135676).

Almost surely, 2^642476551 is an apocalyptic number.

642476551 is a deficient number, since it is larger than the sum of its proper divisors (2066153).

642476551 is a wasteful number, since it uses less digits than its factorization.

642476551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2066152.

The product of its digits is 201600, while the sum is 40.

The square root of 642476551 is about 25347.1211580329. The cubic root of 642476551 is about 862.8840218363.

The spelling of 642476551 in words is "six hundred forty-two million, four hundred seventy-six thousand, five hundred fifty-one".