21734731 has 2 divisors, whose sum is σ = 21734732. Its totient is φ = 21734730.

The previous prime is 21734719. The next prime is 21734749. The reversal of 21734731 is 13743712.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21734731 is a prime.

It is a super-2 number, since 2×21734731² = 944797063284722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21734731.

It is not a weakly prime, because it can be changed into another prime (21734711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10867365 + 10867366.

It is an arithmetic number, because the mean of its divisors is an integer number (10867366).

Almost surely, 2^21734731 is an apocalyptic number.

21734731 is a deficient number, since it is larger than the sum of its proper divisors (1).

21734731 is an equidigital number, since it uses as much as digits as its factorization.

21734731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3528, while the sum is 28.

The square root of 21734731 is about 4662.0522305096. The cubic root of 21734731 is about 279.0731727414.

The spelling of 21734731 in words is "twenty-one million, seven hundred thirty-four thousand, seven hundred thirty-one".