21521627 has 2 divisors, whose sum is σ = 21521628. Its totient is φ = 21521626.

The previous prime is 21521587. The next prime is 21521653. The reversal of 21521627 is 72612512.

It is an a-pointer prime, because the next prime (21521653) can be obtained adding 21521627 to its sum of digits (26).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21521627 - 2¹⁴ = 21505243 is a prime.

It is equal to p_1360862 and since 21521627 and 1360862 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 21521596 and 21521605.

It is not a weakly prime, because it can be changed into another prime (21521527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10760813 + 10760814.

It is an arithmetic number, because the mean of its divisors is an integer number (10760814).

Almost surely, 2^21521627 is an apocalyptic number.

21521627 is a deficient number, since it is larger than the sum of its proper divisors (1).

21521627 is an equidigital number, since it uses as much as digits as its factorization.

21521627 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 26.

The square root of 21521627 is about 4639.1407609599. The cubic root of 21521627 is about 278.1580928851.

The spelling of 21521627 in words is "twenty-one million, five hundred twenty-one thousand, six hundred twenty-seven".