1990259644820 has 24 divisors (see below), whose sum is σ = 4179572460000. Its totient is φ = 796098675872.

The previous prime is 1990259644787. The next prime is 1990259644859. The reversal of 1990259644820 is 284469520991.

It is a happy number.

It is a super-2 number, since 2×1990259644820² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1990259644820.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4811351 + ... + 5208609.

It is an arithmetic number, because the mean of its divisors is an integer number (174148852500).

Almost surely, 2^{1990259644820} is an apocalyptic number.

1990259644820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1990259644820 is an abundant number, since it is smaller than the sum of its proper divisors (2189312815180).

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

1990259644820 is a wasteful number, since it uses less digits than its factorization.

1990259644820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647767 (or 647765 counting only the distinct ones).

The product of its (nonzero) digits is 11197440, while the sum is 59.

The spelling of 1990259644820 in words is "one trillion, nine hundred ninety billion, two hundred fifty-nine million, six hundred forty-four thousand, eight hundred twenty".