55021731 has 8 divisors (see below), whose sum is σ = 73493520. Its totient is φ = 36615552.

The previous prime is 55021723. The next prime is 55021751. The reversal of 55021731 is 13712055.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 55021731 - 2³ = 55021723 is a prime.

It is a super-2 number, since 2×55021731² = 6054781764472722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55021711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14410 + ... + 17823.

It is an arithmetic number, because the mean of its divisors is an integer number (9186690).

Almost surely, 2^55021731 is an apocalyptic number.

55021731 is a deficient number, since it is larger than the sum of its proper divisors (18471789).

55021731 is a wasteful number, since it uses less digits than its factorization.

55021731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32805.

The product of its (nonzero) digits is 1050, while the sum is 24.

The square root of 55021731 is about 7417.6634461264. The cubic root of 55021731 is about 380.3453255174.

Adding to 55021731 its reverse (13712055), we get a palindrome (68733786).

The spelling of 55021731 in words is "fifty-five million, twenty-one thousand, seven hundred thirty-one".