21476731 has 2 divisors, whose sum is σ = 21476732. Its totient is φ = 21476730.

The previous prime is 21476723. The next prime is 21476747. The reversal of 21476731 is 13767412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21476731 - 2³ = 21476723 is a prime.

It is a super-2 number, since 2×21476731² = 922499948892722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21476693 and 21476702.

It is not a weakly prime, because it can be changed into another prime (21476771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10738365 + 10738366.

It is an arithmetic number, because the mean of its divisors is an integer number (10738366).

Almost surely, 2^21476731 is an apocalyptic number.

21476731 is a deficient number, since it is larger than the sum of its proper divisors (1).

21476731 is an equidigital number, since it uses as much as digits as its factorization.

21476731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 31.

The square root of 21476731 is about 4634.2994076775. The cubic root of 21476731 is about 277.9645375119.

The spelling of 21476731 in words is "twenty-one million, four hundred seventy-six thousand, seven hundred thirty-one".