21735937 has 2 divisors, whose sum is σ = 21735938. Its totient is φ = 21735936.

The previous prime is 21735919. The next prime is 21736003. The reversal of 21735937 is 73953712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11082241 + 10653696 = 3329^2 + 3264^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21735937 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21735896 and 21735905.

It is not a weakly prime, because it can be changed into another prime (21735037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10867968 + 10867969.

It is an arithmetic number, because the mean of its divisors is an integer number (10867969).

Almost surely, 2^21735937 is an apocalyptic number.

It is an amenable number.

21735937 is a deficient number, since it is larger than the sum of its proper divisors (1).

21735937 is an equidigital number, since it uses as much as digits as its factorization.

21735937 is an evil number, because the sum of its binary digits is even.

The product of its digits is 39690, while the sum is 37.

The square root of 21735937 is about 4662.1815708958. The cubic root of 21735937 is about 279.0783343117.

The spelling of 21735937 in words is "twenty-one million, seven hundred thirty-five thousand, nine hundred thirty-seven".