531621631 has 4 divisors (see below), whose sum is σ = 532026000. Its totient is φ = 531217264.

The previous prime is 531621613. The next prime is 531621677. The reversal of 531621631 is 136126135.

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-531621631 is a prime.

It is a super-2 number, since 2×531621631² = 565243117094200322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 531621631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (531621611) 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, 200206 + ... + 202843.

It is an arithmetic number, because the mean of its divisors is an integer number (133006500).

Almost surely, 2^531621631 is an apocalyptic number.

531621631 is a deficient number, since it is larger than the sum of its proper divisors (404369).

531621631 is a wasteful number, since it uses less digits than its factorization.

531621631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404368.

The product of its digits is 3240, while the sum is 28.

The square root of 531621631 is about 23056.9215421313. The cubic root of 531621631 is about 810.0917596601.

Adding to 531621631 its reverse (136126135), we get a palindrome (667747766).

The spelling of 531621631 in words is "five hundred thirty-one million, six hundred twenty-one thousand, six hundred thirty-one".