55281639 has 16 divisors (see below), whose sum is σ = 85015040. Its totient is φ = 31298400.

The previous prime is 55281619. The next prime is 55281641. The reversal of 55281639 is 93618255.

It is not a de Polignac number, because 55281639 - 2¹⁵ = 55248871 is a prime.

It is a super-2 number, since 2×55281639² = 6112119221052642, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 55281597 and 55281606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55281619) 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, 9787 + ... + 14364.

It is an arithmetic number, because the mean of its divisors is an integer number (5313440).

Almost surely, 2^55281639 is an apocalyptic number.

55281639 is a deficient number, since it is larger than the sum of its proper divisors (29733401).

55281639 is a wasteful number, since it uses less digits than its factorization.

55281639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24270.

The product of its digits is 64800, while the sum is 39.

The square root of 55281639 is about 7435.1623385102. The cubic root of 55281639 is about 380.9432683284.

The spelling of 55281639 in words is "fifty-five million, two hundred eighty-one thousand, six hundred thirty-nine".