55143990 has 96 divisors (see below), whose sum is σ = 162279936. Its totient is φ = 13361760.

The previous prime is 55143989. The next prime is 55144013. The reversal of 55143990 is 9934155.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25699 + ... + 27761.

It is an arithmetic number, because the mean of its divisors is an integer number (1690416).

Almost surely, 2^55143990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55143990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81139968).

55143990 is an abundant number, since it is smaller than the sum of its proper divisors (107135946).

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

55143990 is a wasteful number, since it uses less digits than its factorization.

55143990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2096 (or 2084 counting only the distinct ones).

The product of its (nonzero) digits is 24300, while the sum is 36.

The square root of 55143990 is about 7425.8999454612. The cubic root of 55143990 is about 380.6268278686.

The spelling of 55143990 in words is "fifty-five million, one hundred forty-three thousand, nine hundred ninety".