21137461 has 2 divisors, whose sum is σ = 21137462. Its totient is φ = 21137460.

The previous prime is 21137453. The next prime is 21137489. The reversal of 21137461 is 16473112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15256836 + 5880625 = 3906^2 + 2425^2 .

It is a cyclic number.

It is not a de Polignac number, because 21137461 - 2³ = 21137453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21134461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10568730 + 10568731.

It is an arithmetic number, because the mean of its divisors is an integer number (10568731).

Almost surely, 2^21137461 is an apocalyptic number.

It is an amenable number.

21137461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21137461 is an equidigital number, since it uses as much as digits as its factorization.

21137461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 25.

The square root of 21137461 is about 4597.5494559602. The cubic root of 21137461 is about 276.4930842904.

The spelling of 21137461 in words is "twenty-one million, one hundred thirty-seven thousand, four hundred sixty-one".