20497920 has 160 divisors (see below), whose sum is σ = 69825888. Its totient is φ = 5111808.

The previous prime is 20497901. The next prime is 20497921. The reversal of 20497920 is 2979402.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20497921) 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, 130482 + ... + 130638.

Almost surely, 2^20497920 is an apocalyptic number.

20497920 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 20497920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34912944).

20497920 is an abundant number, since it is smaller than the sum of its proper divisors (49327968).

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

20497920 is a wasteful number, since it uses less digits than its factorization.

20497920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 20497920 is about 4527.4628656677. The cubic root of 20497920 is about 273.6759270824.

The spelling of 20497920 in words is "twenty million, four hundred ninety-seven thousand, nine hundred twenty".