21776536 has 8 divisors (see below), whose sum is σ = 40831020. Its totient is φ = 10888264.

The previous prime is 21776501. The next prime is 21776537. The reversal of 21776536 is 63567712.

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21776495 and 21776504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21776537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1361026 + ... + 1361041.

Almost surely, 2^21776536 is an apocalyptic number.

It is an amenable number.

21776536 is a deficient number, since it is larger than the sum of its proper divisors (19054484).

21776536 is a wasteful number, since it uses less digits than its factorization.

21776536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2722073 (or 2722069 counting only the distinct ones).

The product of its digits is 52920, while the sum is 37.

The square root of 21776536 is about 4666.5336171510. The cubic root of 21776536 is about 279.2519830522.

The spelling of 21776536 in words is "twenty-one million, seven hundred seventy-six thousand, five hundred thirty-six".