1990447658 has 16 divisors (see below), whose sum is σ = 3033564864. Its totient is φ = 979292160.

The previous prime is 1990447643. The next prime is 1990447661. The reversal of 1990447658 is 8567440991.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax 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, 121898 + ... + 137258.

It is an arithmetic number, because the mean of its divisors is an integer number (189597804).

Almost surely, 2^1990447658 is an apocalyptic number.

1990447658 is a deficient number, since it is larger than the sum of its proper divisors (1043117206).

1990447658 is a wasteful number, since it uses less digits than its factorization.

1990447658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16397.

The product of its (nonzero) digits is 2177280, while the sum is 53.

The square root of 1990447658 is about 44614.4332923775. The cubic root of 1990447658 is about 1257.9119818141.

The spelling of 1990447658 in words is "one billion, nine hundred ninety million, four hundred forty-seven thousand, six hundred fifty-eight".