20953680 has 80 divisors (see below), whose sum is σ = 70870464. Its totient is φ = 5079040.

The previous prime is 20953679. The next prime is 20953687. The reversal of 20953680 is 8635902.

It is a happy number.

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 (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20953687) 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, 1329 + ... + 6608.

Almost surely, 2^20953680 is an apocalyptic number.

20953680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20953680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35435232).

20953680 is an abundant number, since it is smaller than the sum of its proper divisors (49916784).

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

20953680 is a wasteful number, since it uses less digits than its factorization.

20953680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7964 (or 7958 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 20953680 is about 4577.5189786608. The cubic root of 20953680 is about 275.6894216989.

It can be divided in two parts, 2095 and 3680, that added together give a palindrome (5775).

The spelling of 20953680 in words is "twenty million, nine hundred fifty-three thousand, six hundred eighty".