55030991 has 2 divisors, whose sum is σ = 55030992. Its totient is φ = 55030990.

The previous prime is 55030981. The next prime is 55031017. The reversal of 55030991 is 19903055.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55030991 - 2¹⁴ = 55014607 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55030931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27515495 + 27515496.

It is an arithmetic number, because the mean of its divisors is an integer number (27515496).

Almost surely, 2^55030991 is an apocalyptic number.

55030991 is a deficient number, since it is larger than the sum of its proper divisors (1).

55030991 is an equidigital number, since it uses as much as digits as its factorization.

55030991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6075, while the sum is 32.

The square root of 55030991 is about 7418.2876056405. The cubic root of 55030991 is about 380.3666613308.

The spelling of 55030991 in words is "fifty-five million, thirty thousand, nine hundred ninety-one".