55212420 has 48 divisors (see below), whose sum is σ = 161320320. Its totient is φ = 14082816.

The previous prime is 55212401. The next prime is 55212427. The reversal of 55212420 is 2421255.

55212420 = T₃₆₄ + T₃₆₅ + ... + T₇₂₃.

It is a happy number.

It is a super-2 number, since 2×55212420² = 6096822644512800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55212427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18625 + ... + 21384.

It is an arithmetic number, because the mean of its divisors is an integer number (3360840).

Almost surely, 2^55212420 is an apocalyptic number.

It is an amenable number.

55212420 is an abundant number, since it is smaller than the sum of its proper divisors (106107900).

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

55212420 is a wasteful number, since it uses less digits than its factorization.

55212420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40044 (or 40042 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 55212420 is about 7430.5060392950. The cubic root of 55212420 is about 380.7842069251.

Adding to 55212420 its reverse (2421255), we get a palindrome (57633675).

The spelling of 55212420 in words is "fifty-five million, two hundred twelve thousand, four hundred twenty".