21290877 has 16 divisors (see below), whose sum is σ = 31620160. Its totient is φ = 14158800.

The previous prime is 21290839. The next prime is 21290903. The reversal of 21290877 is 77809212.

It is not a de Polignac number, because 21290877 - 2⁶ = 21290813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21290777) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14727 + ... + 16107.

It is an arithmetic number, because the mean of its divisors is an integer number (1976260).

Almost surely, 2^21290877 is an apocalyptic number.

21290877 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21290877 is a deficient number, since it is larger than the sum of its proper divisors (10329283).

21290877 is a wasteful number, since it uses less digits than its factorization.

21290877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1961 (or 1955 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 21290877 is about 4614.2038316485. The cubic root of 21290877 is about 277.1604026946.

The spelling of 21290877 in words is "twenty-one million, two hundred ninety thousand, eight hundred seventy-seven".