21928775 has 24 divisors (see below), whose sum is σ = 30962304. Its totient is φ = 15250400.

The previous prime is 21928769. The next prime is 21928787. The reversal of 21928775 is 57782912.

It is not a de Polignac number, because 21928775 - 2¹⁴ = 21912391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4592 + ... + 8058.

It is an arithmetic number, because the mean of its divisors is an integer number (1290096).

Almost surely, 2^21928775 is an apocalyptic number.

21928775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21928775 is a deficient number, since it is larger than the sum of its proper divisors (9033529).

21928775 is a wasteful number, since it uses less digits than its factorization.

21928775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3511 (or 3506 counting only the distinct ones).

The product of its digits is 70560, while the sum is 41.

The square root of 21928775 is about 4682.8169940753. The cubic root of 21928775 is about 279.9012194072.

The spelling of 21928775 in words is "twenty-one million, nine hundred twenty-eight thousand, seven hundred seventy-five".