55138505 has 8 divisors (see below), whose sum is σ = 66212424. Its totient is φ = 44080000.

The previous prime is 55138487. The next prime is 55138507. The reversal of 55138505 is 50583155.

It can be written as a sum of positive squares in 4 ways, for example, as 8462281 + 46676224 = 2909^2 + 6832^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 55138505 - 2¹⁴ = 55122121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55138507) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6605 + ... + 12405.

It is an arithmetic number, because the mean of its divisors is an integer number (8276553).

Almost surely, 2^55138505 is an apocalyptic number.

It is an amenable number.

55138505 is a deficient number, since it is larger than the sum of its proper divisors (11073919).

55138505 is a wasteful number, since it uses less digits than its factorization.

55138505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7707.

The product of its (nonzero) digits is 15000, while the sum is 32.

The square root of 55138505 is about 7425.5306207705. The cubic root of 55138505 is about 380.6142075306.

The spelling of 55138505 in words is "fifty-five million, one hundred thirty-eight thousand, five hundred five".