21928977 has 24 divisors (see below), whose sum is σ = 36616320. Its totient is φ = 12386880.

The previous prime is 21928969. The next prime is 21928987. The reversal of 21928977 is 77982912.

It is not a de Polignac number, because 21928977 - 2³ = 21928969 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21928957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3652 + ... + 7562.

It is an arithmetic number, because the mean of its divisors is an integer number (1525680).

Almost surely, 2^21928977 is an apocalyptic number.

It is an amenable number.

21928977 is a deficient number, since it is larger than the sum of its proper divisors (14687343).

21928977 is a wasteful number, since it uses less digits than its factorization.

21928977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4013 (or 4010 counting only the distinct ones).

The product of its digits is 127008, while the sum is 45.

The square root of 21928977 is about 4682.8385622398. The cubic root of 21928977 is about 279.9020788544.

The spelling of 21928977 in words is "twenty-one million, nine hundred twenty-eight thousand, nine hundred seventy-seven".