55158021 has 12 divisors (see below), whose sum is σ = 82243200. Its totient is φ = 35585640.

The previous prime is 55157987. The next prime is 55158043. The reversal of 55158021 is 12085155.

It is not a de Polignac number, because 55158021 - 2¹⁴ = 55141637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55151021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 98571 + ... + 99128.

It is an arithmetic number, because the mean of its divisors is an integer number (6853600).

Almost surely, 2^55158021 is an apocalyptic number.

It is an amenable number.

55158021 is a deficient number, since it is larger than the sum of its proper divisors (27085179).

55158021 is a wasteful number, since it uses less digits than its factorization.

55158021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197736 (or 197733 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 27.

The square root of 55158021 is about 7426.8446193522. The cubic root of 55158021 is about 380.6591077365.

The spelling of 55158021 in words is "fifty-five million, one hundred fifty-eight thousand, twenty-one".