1638037121 has 12 divisors (see below), whose sum is σ = 1928434032. Its totient is φ = 1387112328.

The previous prime is 1638037081. The next prime is 1638037123. The reversal of 1638037121 is 1217308361.

It is not a de Polignac number, because 1638037121 - 2¹⁰ = 1638036097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1638037123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 197315 + ... + 205448.

It is an arithmetic number, because the mean of its divisors is an integer number (160702836).

Almost surely, 2^1638037121 is an apocalyptic number.

It is an amenable number.

1638037121 is a deficient number, since it is larger than the sum of its proper divisors (290396911).

1638037121 is an equidigital number, since it uses as much as digits as its factorization.

1638037121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402860 (or 402853 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 1638037121 is about 40472.6712856960. The cubic root of 1638037121 is about 1178.8030381342.

The spelling of 1638037121 in words is "one billion, six hundred thirty-eight million, thirty-seven thousand, one hundred twenty-one".