21654772 has 6 divisors (see below), whose sum is σ = 37895858. Its totient is φ = 10827384.

The previous prime is 21654761. The next prime is 21654781. The reversal of 21654772 is 27745612.

It can be written as a sum of positive squares in only one way, i.e., 12916836 + 8737936 = 3594^2 + 2956^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2706843 + ... + 2706850.

Almost surely, 2^21654772 is an apocalyptic number.

It is an amenable number.

21654772 is a deficient number, since it is larger than the sum of its proper divisors (16241086).

21654772 is a wasteful number, since it uses less digits than its factorization.

21654772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5413697 (or 5413695 counting only the distinct ones).

The product of its digits is 23520, while the sum is 34.

The square root of 21654772 is about 4653.4688136916. The cubic root of 21654772 is about 278.7305286459.

The spelling of 21654772 in words is "twenty-one million, six hundred fifty-four thousand, seven hundred seventy-two".