20899740 has 48 divisors (see below), whose sum is σ = 58988160. Its totient is φ = 5528640.

The previous prime is 20899733. The next prime is 20899751. The reversal of 20899740 is 4799802.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6531 + ... + 9189.

It is an arithmetic number, because the mean of its divisors is an integer number (1228920).

Almost surely, 2^20899740 is an apocalyptic number.

20899740 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 20899740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29494080).

20899740 is an abundant number, since it is smaller than the sum of its proper divisors (38088420).

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

20899740 is a wasteful number, since it uses less digits than its factorization.

20899740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2802 (or 2800 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 20899740 is about 4571.6233440650. The cubic root of 20899740 is about 275.4526539653.

The spelling of 20899740 in words is "twenty million, eight hundred ninety-nine thousand, seven hundred forty".