20552640 has 112 divisors (see below), whose sum is σ = 66324480. Its totient is φ = 5391360.

The previous prime is 20552629. The next prime is 20552647. The reversal of 20552640 is 4625502.

It is a super-2 number, since 2×20552640² = 844822021939200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20552640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20552647) 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, 75705 + ... + 75975.

Almost surely, 2^20552640 is an apocalyptic number.

20552640 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 20552640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33162240).

20552640 is an abundant number, since it is smaller than the sum of its proper divisors (45771840).

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

20552640 is a wasteful number, since it uses less digits than its factorization.

20552640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 370 (or 360 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 20552640 is about 4533.5019576482. The cubic root of 20552640 is about 273.9192402336.

The spelling of 20552640 in words is "twenty million, five hundred fifty-two thousand, six hundred forty".