21902737 has 2 divisors, whose sum is σ = 21902738. Its totient is φ = 21902736.

The previous prime is 21902729. The next prime is 21902753. The reversal of 21902737 is 73720912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18181696 + 3721041 = 4264^2 + 1929^2 .

It is a cyclic number.

It is not a de Polignac number, because 21902737 - 2³ = 21902729 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21902699 and 21902708.

It is not a weakly prime, because it can be changed into another prime (21900737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10951368 + 10951369.

It is an arithmetic number, because the mean of its divisors is an integer number (10951369).

Almost surely, 2^21902737 is an apocalyptic number.

It is an amenable number.

21902737 is a deficient number, since it is larger than the sum of its proper divisors (1).

21902737 is an equidigital number, since it uses as much as digits as its factorization.

21902737 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5292, while the sum is 31.

The square root of 21902737 is about 4680.0360041350. The cubic root of 21902737 is about 279.7903915954.

The spelling of 21902737 in words is "twenty-one million, nine hundred two thousand, seven hundred thirty-seven".