20995740 has 96 divisors (see below), whose sum is σ = 66528000. Its totient is φ = 5495616.

The previous prime is 20995721. The next prime is 20995771. The reversal of 20995740 is 4759902.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20995695 and 20995704.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31531 + ... + 32189.

It is an arithmetic number, because the mean of its divisors is an integer number (693000).

Almost surely, 2^20995740 is an apocalyptic number.

20995740 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 20995740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33264000).

20995740 is an abundant number, since it is smaller than the sum of its proper divisors (45532260).

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

20995740 is a wasteful number, since it uses less digits than its factorization.

20995740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736 (or 728 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 20995740 is about 4582.1108672750. The cubic root of 20995740 is about 275.8737607940.

Multiplying 20995740 by its sum of digits (36), we get a triangular number (755846640 = T₃₈₈₈₀).

The spelling of 20995740 in words is "twenty million, nine hundred ninety-five thousand, seven hundred forty".