120400820 has 48 divisors (see below), whose sum is σ = 257432448. Its totient is φ = 47295360.

The previous prime is 120400811. The next prime is 120400823. The reversal of 120400820 is 28004021.

120400820 = 80² + 81² + ... + 712².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120400823) 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, 434522 + ... + 434798.

It is an arithmetic number, because the mean of its divisors is an integer number (5363176).

Almost surely, 2^120400820 is an apocalyptic number.

120400820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

120400820 is an abundant number, since it is smaller than the sum of its proper divisors (137031628).

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

120400820 is a wasteful number, since it uses less digits than its factorization.

120400820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 600 (or 598 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 120400820 is about 10972.7307448966. The cubic root of 120400820 is about 493.7909751820.

Adding to 120400820 its reverse (28004021), we get a palindrome (148404841).

The spelling of 120400820 in words is "one hundred twenty million, four hundred thousand, eight hundred twenty".