55431389 has 4 divisors (see below), whose sum is σ = 59695356. Its totient is φ = 51167424.

The previous prime is 55431347. The next prime is 55431391. The reversal of 55431389 is 98313455.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8508889 + 46922500 = 2917^2 + 6850^2 .

It is a cyclic number.

It is not a de Polignac number, because 55431389 - 2²⁴ = 38654173 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 (55431319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2131964 + ... + 2131989.

It is an arithmetic number, because the mean of its divisors is an integer number (14923839).

Almost surely, 2^55431389 is an apocalyptic number.

It is an amenable number.

55431389 is a deficient number, since it is larger than the sum of its proper divisors (4263967).

55431389 is a wasteful number, since it uses less digits than its factorization.

55431389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4263966.

The product of its digits is 64800, while the sum is 38.

The square root of 55431389 is about 7445.2259200108. The cubic root of 55431389 is about 381.2869316906.

The spelling of 55431389 in words is "fifty-five million, four hundred thirty-one thousand, three hundred eighty-nine".