1990918144 has 68 divisors (see below), whose sum is σ = 4218389064. Its totient is φ = 936378368.

The previous prime is 1990918133. The next prime is 1990918151. The reversal of 1990918144 is 4418190991.

It is a tau number, because it is divible by the number of its divisors (68).

It is a super-2 number, since 2×1990918144² = 7927510112216809472, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1990918094 and 1990918103.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1113219 + ... + 1115005.

Almost surely, 2^1990918144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1990918144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2109194532).

1990918144 is an abundant number, since it is smaller than the sum of its proper divisors (2227470920).

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

1990918144 is an frugal number, since it uses more digits than its factorization.

1990918144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1836 (or 1806 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 46.

The square root of 1990918144 is about 44619.7057811904. The cubic root of 1990918144 is about 1258.0110857099.

The spelling of 1990918144 in words is "one billion, nine hundred ninety million, nine hundred eighteen thousand, one hundred forty-four".