21269537 has 2 divisors, whose sum is σ = 21269538. Its totient is φ = 21269536.

The previous prime is 21269527. The next prime is 21269551. The reversal of 21269537 is 73596212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12082576 + 9186961 = 3476^2 + 3031^2 .

It is a cyclic number.

It is not a de Polignac number, because 21269537 - 2¹² = 21265441 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21269497 and 21269506.

It is not a weakly prime, because it can be changed into another prime (21269527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10634768 + 10634769.

It is an arithmetic number, because the mean of its divisors is an integer number (10634769).

Almost surely, 2^21269537 is an apocalyptic number.

It is an amenable number.

21269537 is a deficient number, since it is larger than the sum of its proper divisors (1).

21269537 is an equidigital number, since it uses as much as digits as its factorization.

21269537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 35.

The square root of 21269537 is about 4611.8908269819. The cubic root of 21269537 is about 277.0677717807.

The spelling of 21269537 in words is "twenty-one million, two hundred sixty-nine thousand, five hundred thirty-seven".