1660731990 has 32 divisors (see below), whose sum is σ = 4030547040. Its totient is φ = 437885184.

The previous prime is 1660731979. The next prime is 1660732033. The reversal of 1660731990 is 991370661.

1660731990 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 308329 + ... + 313668.

It is an arithmetic number, because the mean of its divisors is an integer number (125954595).

Almost surely, 2^1660731990 is an apocalyptic number.

1660731990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1660731990 is an abundant number, since it is smaller than the sum of its proper divisors (2369815050).

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

1660731990 is a wasteful number, since it uses less digits than its factorization.

1660731990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622096.

The product of its (nonzero) digits is 61236, while the sum is 42.

The square root of 1660731990 is about 40752.0795788387. The cubic root of 1660731990 is about 1184.2221604024. Note that the first 3 decimals are identical.

The spelling of 1660731990 in words is "one billion, six hundred sixty million, seven hundred thirty-one thousand, nine hundred ninety".