1981668598 has 32 divisors (see below), whose sum is σ = 3660906816. Its totient is φ = 783433728.

The previous prime is 1981668547. The next prime is 1981668599. The reversal of 1981668598 is 8958661891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981668599) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 381990 + ... + 387142.

It is an arithmetic number, because the mean of its divisors is an integer number (114403338).

Almost surely, 2^1981668598 is an apocalyptic number.

1981668598 is a deficient number, since it is larger than the sum of its proper divisors (1679238218).

1981668598 is a wasteful number, since it uses less digits than its factorization.

1981668598 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7288.

The product of its digits is 7464960, while the sum is 61.

The square root of 1981668598 is about 44515.9364497704. The cubic root of 1981668598 is about 1256.0598757580.

The spelling of 1981668598 in words is "one billion, nine hundred eighty-one million, six hundred sixty-eight thousand, five hundred ninety-eight".