55397790 has 64 divisors (see below), whose sum is σ = 168837120. Its totient is φ = 12661920.

The previous prime is 55397789. The next prime is 55397791. The reversal of 55397790 is 9779355.

It is a happy number.

55397790 is a `hidden beast` number, since 553 + 9 + 7 + 7 + 90 = 666.

It is an interprime number because it is at equal distance from previous prime (55397789) and next prime (55397791).

It is a super-3 number, since 3×55397790³ (a number of 24 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55397791) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12766 + ... + 16545.

It is an arithmetic number, because the mean of its divisors is an integer number (2638080).

Almost surely, 2^55397790 is an apocalyptic number.

55397790 is an abundant number, since it is smaller than the sum of its proper divisors (113439330).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55397790 is a wasteful number, since it uses less digits than its factorization.

55397790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29334 (or 29328 counting only the distinct ones).

The product of its (nonzero) digits is 297675, while the sum is 45.

The square root of 55397790 is about 7442.9691655951. The cubic root of 55397790 is about 381.2098787843.

The spelling of 55397790 in words is "fifty-five million, three hundred ninety-seven thousand, seven hundred ninety".