55640520 has 160 divisors (see below), whose sum is σ = 201552120. Its totient is φ = 13685760.

The previous prime is 55640509. The next prime is 55640521. The reversal of 55640520 is 2504655.

It can be written as a sum of positive squares in 4 ways, for example, as 47032164 + 8608356 = 6858^2 + 2934^2 .

It is a super-3 number, since 3×55640520³ (a number of 24 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (55640521) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 41460 + ... + 42780.

Almost surely, 2^55640520 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 55640520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100776060).

55640520 is an abundant number, since it is smaller than the sum of its proper divisors (145911600).

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

55640520 is a wasteful number, since it uses less digits than its factorization.

55640520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1357 (or 1344 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 27.

The square root of 55640520 is about 7459.2573356870. The cubic root of 55640520 is about 381.7658351242.

The spelling of 55640520 in words is "fifty-five million, six hundred forty thousand, five hundred twenty".