21977725 has 48 divisors (see below), whose sum is σ = 34819200. Its totient is φ = 13641600.

The previous prime is 21977713. The next prime is 21977743. The reversal of 21977725 is 52777912.

It is a happy number.

It is not a de Polignac number, because 21977725 - 2¹³ = 21969533 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 94209 + ... + 94441.

It is an arithmetic number, because the mean of its divisors is an integer number (725400).

Almost surely, 2^21977725 is an apocalyptic number.

21977725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21977725 is a deficient number, since it is larger than the sum of its proper divisors (12841475).

21977725 is a wasteful number, since it uses less digits than its factorization.

21977725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275 (or 256 counting only the distinct ones).

The product of its digits is 61740, while the sum is 40.

The square root of 21977725 is about 4688.0406354894. The cubic root of 21977725 is about 280.1093323032.

The spelling of 21977725 in words is "twenty-one million, nine hundred seventy-seven thousand, seven hundred twenty-five".