55621559 has 4 divisors (see below), whose sum is σ = 63567504. Its totient is φ = 47675616.

The previous prime is 55621549. The next prime is 55621561. The reversal of 55621559 is 95512655.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55621559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55621519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3972962 + ... + 3972975.

It is an arithmetic number, because the mean of its divisors is an integer number (15891876).

Almost surely, 2^55621559 is an apocalyptic number.

55621559 is a deficient number, since it is larger than the sum of its proper divisors (7945945).

55621559 is an equidigital number, since it uses as much as digits as its factorization.

55621559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7945944.

The product of its digits is 67500, while the sum is 38.

The square root of 55621559 is about 7457.9862563563. The cubic root of 55621559 is about 381.7224645470.

The spelling of 55621559 in words is "fifty-five million, six hundred twenty-one thousand, five hundred fifty-nine".