55999990 has 8 divisors (see below), whose sum is σ = 100800000. Its totient is φ = 22399992.

The previous prime is 55999987. The next prime is 55999991. The reversal of 55999990 is 9999955.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55999991) 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, 2799990 + ... + 2800009.

It is an arithmetic number, because the mean of its divisors is an integer number (12600000).

Almost surely, 2^55999990 is an apocalyptic number.

55999990 is a deficient number, since it is larger than the sum of its proper divisors (44800010).

55999990 is a wasteful number, since it uses less digits than its factorization.

55999990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5600006.

The product of its (nonzero) digits is 1476225, while the sum is 55.

The square root of 55999990 is about 7483.3141053947. The cubic root of 55999990 is about 382.5862137815.

It can be divided in two parts, 5 and 5999990, that added together give a palindrome (5999995).

The spelling of 55999990 in words is "fifty-five million, nine hundred ninety-nine thousand, nine hundred ninety".