55329991 has 2 divisors, whose sum is σ = 55329992. Its totient is φ = 55329990.

The previous prime is 55329983. The next prime is 55329997. The reversal of 55329991 is 19992355.

55329991 is nontrivially palindromic in base 4.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 55329991 - 2³ = 55329983 is a prime.

It is a super-2 number, since 2×55329991² = 6122815808120162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55329997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27664995 + 27664996.

It is an arithmetic number, because the mean of its divisors is an integer number (27664996).

Almost surely, 2^55329991 is an apocalyptic number.

55329991 is a deficient number, since it is larger than the sum of its proper divisors (1).

55329991 is an equidigital number, since it uses as much as digits as its factorization.

55329991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 109350, while the sum is 43.

The square root of 55329991 is about 7438.4132044409. The cubic root of 55329991 is about 381.0542997769.

The spelling of 55329991 in words is "fifty-five million, three hundred twenty-nine thousand, nine hundred ninety-one".