55390555 has 16 divisors (see below), whose sum is σ = 75665664. Its totient is φ = 38531680.

The previous prime is 55390553. The next prime is 55390561. The reversal of 55390555 is 55509355.

It is not a de Polignac number, because 55390555 - 2¹ = 55390553 is a prime.

It is a super-2 number, since 2×55390555² = 6136227166416050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55390553) 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, 20629 + ... + 23158.

It is an arithmetic number, because the mean of its divisors is an integer number (4729104).

Almost surely, 2^55390555 is an apocalyptic number.

55390555 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

55390555 is a deficient number, since it is larger than the sum of its proper divisors (20275109).

55390555 is a wasteful number, since it uses less digits than its factorization.

55390555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43826.

The product of its (nonzero) digits is 84375, while the sum is 37.

The square root of 55390555 is about 7442.4831205721. The cubic root of 55390555 is about 381.1932826135.

It can be divided in two parts, 55390 and 555, that added together give a triangular number (55945 = T₃₃₄).

The spelling of 55390555 in words is "fifty-five million, three hundred ninety thousand, five hundred fifty-five".