21062657 has 16 divisors (see below), whose sum is σ = 26973312. Its totient is φ = 15966720.

The previous prime is 21062633. The next prime is 21062663. The reversal of 21062657 is 75626012.

It is not a de Polignac number, because 21062657 - 2⁶ = 21062593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21062057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 848 + ... + 6545.

It is an arithmetic number, because the mean of its divisors is an integer number (1685832).

Almost surely, 2^21062657 is an apocalyptic number.

It is an amenable number.

21062657 is a deficient number, since it is larger than the sum of its proper divisors (5910655).

21062657 is a wasteful number, since it uses less digits than its factorization.

21062657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7448.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 21062657 is about 4589.4070423095. The cubic root of 21062657 is about 276.1665355298.

Adding to 21062657 its reverse (75626012), we get a palindrome (96688669).

The spelling of 21062657 in words is "twenty-one million, sixty-two thousand, six hundred fifty-seven".