20993520 has 40 divisors (see below), whose sum is σ = 65080656. Its totient is φ = 5598208.

The previous prime is 20993513. The next prime is 20993527. The reversal of 20993520 is 2539902.

It is an interprime number because it is at equal distance from previous prime (20993513) and next prime (20993527).

It is a tau number, because it is divible by the number of its divisors (40).

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

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20993527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43497 + ... + 43976.

Almost surely, 2^20993520 is an apocalyptic number.

20993520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20993520 is an abundant number, since it is smaller than the sum of its proper divisors (44087136).

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

20993520 is a wasteful number, since it uses less digits than its factorization.

20993520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87489 (or 87483 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 30.

The square root of 20993520 is about 4581.8686144411. The cubic root of 20993520 is about 275.8640372130.

The spelling of 20993520 in words is "twenty million, nine hundred ninety-three thousand, five hundred twenty".