55431551 has 4 divisors (see below), whose sum is σ = 63350352. Its totient is φ = 47512752.

The previous prime is 55431547. The next prime is 55431553. The reversal of 55431551 is 15513455.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 55431551 - 2² = 55431547 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55431553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3959390 + ... + 3959403.

It is an arithmetic number, because the mean of its divisors is an integer number (15837588).

Almost surely, 2^55431551 is an apocalyptic number.

55431551 is a deficient number, since it is larger than the sum of its proper divisors (7918801).

55431551 is an equidigital number, since it uses as much as digits as its factorization.

55431551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7918800.

The product of its digits is 7500, while the sum is 29.

The square root of 55431551 is about 7445.2367994578. The cubic root of 55431551 is about 381.2873031313.

The spelling of 55431551 in words is "fifty-five million, four hundred thirty-one thousand, five hundred fifty-one".