20953660 has 96 divisors (see below), whose sum is σ = 56165760. Its totient is φ = 6386688.

The previous prime is 20953643. The next prime is 20953663. The reversal of 20953660 is 6635902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20953663) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52582 + ... + 52978.

It is an arithmetic number, because the mean of its divisors is an integer number (585060).

Almost surely, 2^20953660 is an apocalyptic number.

20953660 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 20953660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28082880).

20953660 is an abundant number, since it is smaller than the sum of its proper divisors (35212100).

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

20953660 is a wasteful number, since it uses less digits than its factorization.

20953660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455 (or 453 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 31.

The square root of 20953660 is about 4577.5167940708. The cubic root of 20953660 is about 275.6893339849.

The spelling of 20953660 in words is "twenty million, nine hundred fifty-three thousand, six hundred sixty".