1990721124 has 384 divisors, whose sum is σ = 6612480000. Its totient is φ = 511443072.

The previous prime is 1990721111. The next prime is 1990721147. The reversal of 1990721124 is 4211270991.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 33741007 + ... + 33741065.

It is an arithmetic number, because the mean of its divisors is an integer number (17220000).

Almost surely, 2^1990721124 is an apocalyptic number.

1990721124 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1990721124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3306240000).

1990721124 is an abundant number, since it is smaller than the sum of its proper divisors (4621758876).

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

1990721124 is a wasteful number, since it uses less digits than its factorization.

1990721124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 1990721124 is about 44617.4979576399. The cubic root of 1990721124 is about 1257.9695870139.

The spelling of 1990721124 in words is "one billion, nine hundred ninety million, seven hundred twenty-one thousand, one hundred twenty-four".