55561723439 has 2 divisors, whose sum is σ = 55561723440. Its totient is φ = 55561723438.

The previous prime is 55561723411. The next prime is 55561723487. The reversal of 55561723439 is 93432716555.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55561723439 - 2²⁰ = 55560674863 is a prime.

It is a super-2 number, since 2×55561723439² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55561723409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27780861719 + 27780861720.

It is an arithmetic number, because the mean of its divisors is an integer number (27780861720).

Almost surely, 2^55561723439 is an apocalyptic number.

55561723439 is a deficient number, since it is larger than the sum of its proper divisors (1).

55561723439 is an equidigital number, since it uses as much as digits as its factorization.

55561723439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3402000, while the sum is 50.

The spelling of 55561723439 in words is "fifty-five billion, five hundred sixty-one million, seven hundred twenty-three thousand, four hundred thirty-nine".