20955720 has 32 divisors (see below), whose sum is σ = 62867520. Its totient is φ = 5588160.

The previous prime is 20955707. The next prime is 20955731. The reversal of 20955720 is 2755902.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87196 + ... + 87435.

It is an arithmetic number, because the mean of its divisors is an integer number (1964610).

Almost surely, 2^20955720 is an apocalyptic number.

20955720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20955720 is an abundant number, since it is smaller than the sum of its proper divisors (41911800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20955720 is a wasteful number, since it uses less digits than its factorization.

20955720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174645 (or 174641 counting only the distinct ones).

The product of its (nonzero) digits is 6300, while the sum is 30.

The square root of 20955720 is about 4577.7418013689. The cubic root of 20955720 is about 275.6983682287.

The spelling of 20955720 in words is "twenty million, nine hundred fifty-five thousand, seven hundred twenty".