21340415731 has 2 divisors, whose sum is σ = 21340415732. Its totient is φ = 21340415730.

The previous prime is 21340415693. The next prime is 21340415737. The reversal of 21340415731 is 13751404312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21340415731 - 2⁹ = 21340415219 is a prime.

It is a super-2 number, since 2×21340415731² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21340415693 and 21340415702.

It is not a weakly prime, because it can be changed into another prime (21340415737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10670207865 + 10670207866.

It is an arithmetic number, because the mean of its divisors is an integer number (10670207866).

Almost surely, 2^21340415731 is an apocalyptic number.

21340415731 is a deficient number, since it is larger than the sum of its proper divisors (1).

21340415731 is an equidigital number, since it uses as much as digits as its factorization.

21340415731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 31.

The spelling of 21340415731 in words is "twenty-one billion, three hundred forty million, four hundred fifteen thousand, seven hundred thirty-one".