55858821 has 16 divisors (see below), whose sum is σ = 79035264. Its totient is φ = 34970624.

The previous prime is 55858819. The next prime is 55858837. The reversal of 55858821 is 12885855.

It is a cyclic number.

It is not a de Polignac number, because 55858821 - 2¹ = 55858819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55858801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29320 + ... + 31166.

It is an arithmetic number, because the mean of its divisors is an integer number (4939704).

Almost surely, 2^55858821 is an apocalyptic number.

55858821 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

55858821 is a deficient number, since it is larger than the sum of its proper divisors (23176443).

55858821 is a wasteful number, since it uses less digits than its factorization.

55858821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2460.

The product of its digits is 128000, while the sum is 42.

The square root of 55858821 is about 7473.8759021006. The cubic root of 55858821 is about 382.2644591975.

The spelling of 55858821 in words is "fifty-five million, eight hundred fifty-eight thousand, eight hundred twenty-one".