21928077 has 12 divisors (see below), whose sum is σ = 32847360. Its totient is φ = 14618556.

The previous prime is 21928043. The next prime is 21928099. The reversal of 21928077 is 77082912.

It is not a de Polignac number, because 21928077 - 2⁷ = 21927949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21928877) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44877 + ... + 45362.

It is an arithmetic number, because the mean of its divisors is an integer number (2737280).

Almost surely, 2^21928077 is an apocalyptic number.

21928077 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21928077 is a deficient number, since it is larger than the sum of its proper divisors (10919283).

21928077 is an frugal number, since it uses more digits than its factorization.

21928077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90254 (or 90242 counting only the distinct ones).

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

The square root of 21928077 is about 4682.7424656925. The cubic root of 21928077 is about 279.8982495936.

The spelling of 21928077 in words is "twenty-one million, nine hundred twenty-eight thousand, seventy-seven".