21577772 has 12 divisors (see below), whose sum is σ = 39403056. Its totient is φ = 10319760.

The previous prime is 21577757. The next prime is 21577789. The reversal of 21577772 is 27777512.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117179 + ... + 117362.

It is an arithmetic number, because the mean of its divisors is an integer number (3283588).

Almost surely, 2^21577772 is an apocalyptic number.

It is an amenable number.

21577772 is a deficient number, since it is larger than the sum of its proper divisors (17825284).

21577772 is a wasteful number, since it uses less digits than its factorization.

21577772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234568 (or 234566 counting only the distinct ones).

The product of its digits is 48020, while the sum is 38.

The square root of 21577772 is about 4645.1880478620. The cubic root of 21577772 is about 278.3997664540.

The spelling of 21577772 in words is "twenty-one million, five hundred seventy-seven thousand, seven hundred seventy-two".