55399639 has 2 divisors, whose sum is σ = 55399640. Its totient is φ = 55399638.

The previous prime is 55399637. The next prime is 55399661. The reversal of 55399639 is 93699355.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55399639 - 2¹ = 55399637 is a prime.

Together with 55399637, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 55399592 and 55399601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55399637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27699819 + 27699820.

It is an arithmetic number, because the mean of its divisors is an integer number (27699820).

Almost surely, 2^55399639 is an apocalyptic number.

55399639 is a deficient number, since it is larger than the sum of its proper divisors (1).

55399639 is an equidigital number, since it uses as much as digits as its factorization.

55399639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 984150, while the sum is 49.

The square root of 55399639 is about 7443.0933757410. The cubic root of 55399639 is about 381.2141199236.

The spelling of 55399639 in words is "fifty-five million, three hundred ninety-nine thousand, six hundred thirty-nine".