642267649 has 3 divisors (see below), whose sum is σ = 642292993. Its totient is φ = 642242306.

The previous prime is 642267589. The next prime is 642267653. The reversal of 642267649 is 946762246.

The square root of 642267649 is 25343.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a de Polignac number, because none of the positive numbers 2^k-642267649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642267599 and 642267608.

It is not an unprimeable number, because it can be changed into a prime (642267449) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 12672 + ... + 38014.

Almost surely, 2^642267649 is an apocalyptic number.

642267649 is the 25343-rd square number.

642267649 is the 12672-nd centered octagonal number.

It is an amenable number.

642267649 is a deficient number, since it is larger than the sum of its proper divisors (25344).

642267649 is an frugal number, since it uses more digits than its factorization.

642267649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50686 (or 25343 counting only the distinct ones).

The product of its digits is 870912, while the sum is 46.

The cubic root of 642267649 is about 862.7904891161.

The spelling of 642267649 in words is "six hundred forty-two million, two hundred sixty-seven thousand, six hundred forty-nine".