120400055621 has 18 divisors (see below), whose sum is σ = 133701792882. Its totient is φ = 108390705280.

The previous prime is 120400055603. The next prime is 120400055687. The reversal of 120400055621 is 126550004021.

It can be written as a sum of positive squares in 3 ways, for example, as 72476716225 + 47923339396 = 269215^2 + 218914^2 .

It is not a de Polignac number, because 120400055621 - 2¹⁰ = 120400054597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120400055021) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 240890 + ... + 546651.

Almost surely, 2^120400055621 is an apocalyptic number.

It is an amenable number.

120400055621 is a deficient number, since it is larger than the sum of its proper divisors (13301737261).

120400055621 is an equidigital number, since it uses as much as digits as its factorization.

120400055621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 787621 (or 787581 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 120400055621 its reverse (126550004021), we get a palindrome (246950059642).

The spelling of 120400055621 in words is "one hundred twenty billion, four hundred million, fifty-five thousand, six hundred twenty-one".