55071820 has 24 divisors (see below), whose sum is σ = 118342224. Its totient is φ = 21516096.

The previous prime is 55071817. The next prime is 55071829. The reversal of 55071820 is 2817055.

It is a super-2 number, since 2×55071820² = 6065810716224800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55071829) 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, 31159 + ... + 32878.

It is an arithmetic number, because the mean of its divisors is an integer number (4930926).

Almost surely, 2^55071820 is an apocalyptic number.

It is an amenable number.

55071820 is an abundant number, since it is smaller than the sum of its proper divisors (63270404).

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

55071820 is a wasteful number, since it uses less digits than its factorization.

55071820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64089 (or 64087 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 28.

The square root of 55071820 is about 7421.0390108124. The cubic root of 55071820 is about 380.4607062257.

Adding to 55071820 its reverse (2817055), we get a palindrome (57888875).

The spelling of 55071820 in words is "fifty-five million, seventy-one thousand, eight hundred twenty".