21138776 has 16 divisors (see below), whose sum is σ = 40914240. Its totient is φ = 10228320.

The previous prime is 21138751. The next prime is 21138781. The reversal of 21138776 is 67783112.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42371 + ... + 42866.

It is an arithmetic number, because the mean of its divisors is an integer number (2557140).

Almost surely, 2^21138776 is an apocalyptic number.

It is an amenable number.

21138776 is a deficient number, since it is larger than the sum of its proper divisors (19775464).

21138776 is a wasteful number, since it uses less digits than its factorization.

21138776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85274 (or 85270 counting only the distinct ones).

The product of its digits is 14112, while the sum is 35.

The square root of 21138776 is about 4597.6924647044. The cubic root of 21138776 is about 276.4988178845.

The spelling of 21138776 in words is "twenty-one million, one hundred thirty-eight thousand, seven hundred seventy-six".