20627721 has 12 divisors (see below), whose sum is σ = 30031872. Its totient is φ = 13642776.

The previous prime is 20627713. The next prime is 20627731. The reversal of 20627721 is 12772602.

It is not a de Polignac number, because 20627721 - 2³ = 20627713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20627731) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7881 + ... + 10166.

It is an arithmetic number, because the mean of its divisors is an integer number (2502656).

Almost surely, 2^20627721 is an apocalyptic number.

It is an amenable number.

20627721 is a deficient number, since it is larger than the sum of its proper divisors (9404151).

20627721 is a wasteful number, since it uses less digits than its factorization.

20627721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18180 (or 18177 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 20627721 is about 4541.7750935069. The cubic root of 20627721 is about 274.2523870175.

The spelling of 20627721 in words is "twenty million, six hundred twenty-seven thousand, seven hundred twenty-one".