20391552 has 96 divisors (see below), whose sum is σ = 60677760. Its totient is φ = 6566400.

The previous prime is 20391487. The next prime is 20391557. The reversal of 20391552 is 25519302.

20391552 is a `hidden beast` number, since 20 + 3 + 91 + 552 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (20391557) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35427 + ... + 35997.

It is an arithmetic number, because the mean of its divisors is an integer number (632060).

Almost surely, 2^20391552 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20391552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30338880).

20391552 is an abundant number, since it is smaller than the sum of its proper divisors (40286208).

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

20391552 is a wasteful number, since it uses less digits than its factorization.

20391552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622 (or 607 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 20391552 is about 4515.7006100936. The cubic root of 20391552 is about 273.2017186435.

The spelling of 20391552 in words is "twenty million, three hundred ninety-one thousand, five hundred fifty-two".