21462731 has 2 divisors, whose sum is σ = 21462732. Its totient is φ = 21462730.

The previous prime is 21462689. The next prime is 21462751. The reversal of 21462731 is 13726412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21462731 is a prime.

It is a super-2 number, since 2×21462731² = 921297643956722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21462731.

It is not a weakly prime, because it can be changed into another prime (21462751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10731365 + 10731366.

It is an arithmetic number, because the mean of its divisors is an integer number (10731366).

Almost surely, 2^21462731 is an apocalyptic number.

21462731 is a deficient number, since it is larger than the sum of its proper divisors (1).

21462731 is an equidigital number, since it uses as much as digits as its factorization.

21462731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 26.

The square root of 21462731 is about 4632.7886850147. The cubic root of 21462731 is about 277.9041256269.

The spelling of 21462731 in words is "twenty-one million, four hundred sixty-two thousand, seven hundred thirty-one".