55213520 has 40 divisors (see below), whose sum is σ = 128682240. Its totient is φ = 22032000.

The previous prime is 55213519. The next prime is 55213531. The reversal of 55213520 is 2531255.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59621 + ... + 60539.

It is an arithmetic number, because the mean of its divisors is an integer number (3217056).

Almost surely, 2^55213520 is an apocalyptic number.

It is an amenable number.

55213520 is an abundant number, since it is smaller than the sum of its proper divisors (73468720).

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

55213520 is a wasteful number, since it uses less digits than its factorization.

55213520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1683 (or 1677 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 23.

The square root of 55213520 is about 7430.5800581112. The cubic root of 55213520 is about 380.7867357030.

Adding to 55213520 its reverse (2531255), we get a palindrome (57744775).

The spelling of 55213520 in words is "fifty-five million, two hundred thirteen thousand, five hundred twenty".