21620763 has 20 divisors (see below), whose sum is σ = 32443488. Its totient is φ = 14348880.

The previous prime is 21620749. The next prime is 21620789. The reversal of 21620763 is 36702612.

It is a happy number.

It is not a de Polignac number, because 21620763 - 2⁸ = 21620507 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (21620723) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 23278 + ... + 24188.

Almost surely, 2^21620763 is an apocalyptic number.

21620763 is a deficient number, since it is larger than the sum of its proper divisors (10822725).

21620763 is an equidigital number, since it uses as much as digits as its factorization.

21620763 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216 (or 1207 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 21620763 is about 4649.8132220553. The cubic root of 21620763 is about 278.5845359851.

The spelling of 21620763 in words is "twenty-one million, six hundred twenty thousand, seven hundred sixty-three".