21050613 has 24 divisors (see below), whose sum is σ = 32198400. Its totient is φ = 13215744.

The previous prime is 21050611. The next prime is 21050629. The reversal of 21050613 is 31605012.

21050613 is a `hidden beast` number, since 2 + 1 + 0 + 50 + 613 = 666.

It is not a de Polignac number, because 21050613 - 2¹ = 21050611 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21050611) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 43708 + ... + 44186.

It is an arithmetic number, because the mean of its divisors is an integer number (1341600).

Almost surely, 2^21050613 is an apocalyptic number.

It is an amenable number.

21050613 is a deficient number, since it is larger than the sum of its proper divisors (11147787).

21050613 is a wasteful number, since it uses less digits than its factorization.

21050613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761 (or 758 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 21050613 is about 4588.0947025971. The cubic root of 21050613 is about 276.1138865226.

Adding to 21050613 its reverse (31605012), we get a palindrome (52655625).

The spelling of 21050613 in words is "twenty-one million, fifty thousand, six hundred thirteen".