21372713 has 2 divisors, whose sum is σ = 21372714. Its totient is φ = 21372712.

The previous prime is 21372697. The next prime is 21372719. The reversal of 21372713 is 31727312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20178064 + 1194649 = 4492^2 + 1093^2 .

It is a cyclic number.

It is not a de Polignac number, because 21372713 - 2⁴ = 21372697 is a prime.

It is not a weakly prime, because it can be changed into another prime (21372719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10686356 + 10686357.

It is an arithmetic number, because the mean of its divisors is an integer number (10686357).

Almost surely, 2^21372713 is an apocalyptic number.

It is an amenable number.

21372713 is a deficient number, since it is larger than the sum of its proper divisors (1).

21372713 is an equidigital number, since it uses as much as digits as its factorization.

21372713 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1764, while the sum is 26.

The square root of 21372713 is about 4623.0631620171. The cubic root of 21372713 is about 277.5150569435.

The spelling of 21372713 in words is "twenty-one million, three hundred seventy-two thousand, seven hundred thirteen".