21915701 has 2 divisors, whose sum is σ = 21915702. Its totient is φ = 21915700.

The previous prime is 21915697. The next prime is 21915739. The reversal of 21915701 is 10751912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21613201 + 302500 = 4649^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 21915701 - 2² = 21915697 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21915781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10957850 + 10957851.

It is an arithmetic number, because the mean of its divisors is an integer number (10957851).

Almost surely, 2^21915701 is an apocalyptic number.

It is an amenable number.

21915701 is a deficient number, since it is larger than the sum of its proper divisors (1).

21915701 is an equidigital number, since it uses as much as digits as its factorization.

21915701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 630, while the sum is 26.

The square root of 21915701 is about 4681.4208313289. The cubic root of 21915701 is about 279.8455823726.

The spelling of 21915701 in words is "twenty-one million, nine hundred fifteen thousand, seven hundred one".