20949520 has 40 divisors (see below), whose sum is σ = 49104000. Its totient is φ = 8311680.

The previous prime is 20949499. The next prime is 20949529. The reversal of 20949520 is 2594902.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (20949529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9481 + ... + 11479.

It is an arithmetic number, because the mean of its divisors is an integer number (1227600).

Almost surely, 2^20949520 is an apocalyptic number.

20949520 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 20949520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24552000).

20949520 is an abundant number, since it is smaller than the sum of its proper divisors (28154480).

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

20949520 is a wasteful number, since it uses less digits than its factorization.

20949520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2143 (or 2137 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 20949520 is about 4577.0645614848. The cubic root of 20949520 is about 275.6711759954.

It can be divided in two parts, 209 and 49520, that added together give a square (49729 = 223²).

The spelling of 20949520 in words is "twenty million, nine hundred forty-nine thousand, five hundred twenty".