55801998 has 48 divisors (see below), whose sum is σ = 139501440. Its totient is φ = 15790608.

The previous prime is 55801937. The next prime is 55802017. The reversal of 55801998 is 89910855.

55801998 is a `hidden beast` number, since 558 + 0 + 1 + 9 + 98 = 666.

It is a super-2 number, since 2×55801998² = 6227725961584008, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11413 + ... + 15551.

It is an arithmetic number, because the mean of its divisors is an integer number (2906280).

Almost surely, 2^55801998 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55801998, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69750720).

55801998 is an abundant number, since it is smaller than the sum of its proper divisors (83699442).

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

55801998 is a wasteful number, since it uses less digits than its factorization.

55801998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4261 (or 4258 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 45.

The square root of 55801998 is about 7470.0734936144. The cubic root of 55801998 is about 382.1347943114.

The spelling of 55801998 in words is "fifty-five million, eight hundred one thousand, nine hundred ninety-eight".