20993040 has 80 divisors (see below), whose sum is σ = 72316800. Its totient is φ = 5597568.

The previous prime is 20993039. The next prime is 20993041. The reversal of 20993040 is 4039902.

It is an interprime number because it is at equal distance from previous prime (20993039) and next prime (20993041).

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a junction number, because it is equal to n+sod(n) for n = 20992995 and 20993013.

It is not an unprimeable number, because it can be changed into a prime (20993041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2700 + ... + 7019.

It is an arithmetic number, because the mean of its divisors is an integer number (903960).

Almost surely, 2^20993040 is an apocalyptic number.

20993040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20993040 is an abundant number, since it is smaller than the sum of its proper divisors (51323760).

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

20993040 is a wasteful number, since it uses less digits than its factorization.

20993040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9741 (or 9729 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 20993040 is about 4581.8162337658. The cubic root of 20993040 is about 275.8619347269.

The spelling of 20993040 in words is "twenty million, nine hundred ninety-three thousand, forty".