55212870 has 16 divisors (see below), whose sum is σ = 132510960. Its totient is φ = 14723424.

The previous prime is 55212823. The next prime is 55212877. The reversal of 55212870 is 7821255.

It is a super-2 number, since 2×55212870² = 6096922027273800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 1840429 = 55212870 / (5 + 5 + 2 + 1 + 2 + 8 + 7 + 0).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55212877) 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, 920185 + ... + 920244.

It is an arithmetic number, because the mean of its divisors is an integer number (8281935).

Almost surely, 2^55212870 is an apocalyptic number.

55212870 is an abundant number, since it is smaller than the sum of its proper divisors (77298090).

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

55212870 is a wasteful number, since it uses less digits than its factorization.

55212870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1840439.

The product of its (nonzero) digits is 5600, while the sum is 30.

The square root of 55212870 is about 7430.5363198090. The cubic root of 55212870 is about 380.7852414292.

The spelling of 55212870 in words is "fifty-five million, two hundred twelve thousand, eight hundred seventy".