21174631 has 2 divisors, whose sum is σ = 21174632. Its totient is φ = 21174630.

The previous prime is 21174617. The next prime is 21174641. The reversal of 21174631 is 13647112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21174631 - 2¹¹ = 21172583 is a prime.

It is a super-2 number, since 2×21174631² = 896729995972322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21174596 and 21174605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21174641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10587315 + 10587316.

It is an arithmetic number, because the mean of its divisors is an integer number (10587316).

Almost surely, 2^21174631 is an apocalyptic number.

21174631 is a deficient number, since it is larger than the sum of its proper divisors (1).

21174631 is an equidigital number, since it uses as much as digits as its factorization.

21174631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 25.

The square root of 21174631 is about 4601.5900512758. The cubic root of 21174631 is about 276.6550594314.

The spelling of 21174631 in words is "twenty-one million, one hundred seventy-four thousand, six hundred thirty-one".