21150637 has 2 divisors, whose sum is σ = 21150638. Its totient is φ = 21150636.

The previous prime is 21150631. The next prime is 21150653. The reversal of 21150637 is 73605112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19527561 + 1623076 = 4419^2 + 1274^2 .

It is a cyclic number.

It is not a de Polignac number, because 21150637 - 2¹⁵ = 21117869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21150631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575318 + 10575319.

It is an arithmetic number, because the mean of its divisors is an integer number (10575319).

Almost surely, 2^21150637 is an apocalyptic number.

It is an amenable number.

21150637 is a deficient number, since it is larger than the sum of its proper divisors (1).

21150637 is an equidigital number, since it uses as much as digits as its factorization.

21150637 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 21150637 is about 4598.9821700024. The cubic root of 21150637 is about 276.5505228537.

Adding to 21150637 its reverse (73605112), we get a palindrome (94755749).

The spelling of 21150637 in words is "twenty-one million, one hundred fifty thousand, six hundred thirty-seven".