1990933978 has 8 divisors (see below), whose sum is σ = 3257892000. Its totient is φ = 904969980.

The previous prime is 1990933969. The next prime is 1990933979. The reversal of 1990933978 is 8793390991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1990933979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45248478 + ... + 45248521.

It is an arithmetic number, because the mean of its divisors is an integer number (407236500).

Almost surely, 2^1990933978 is an apocalyptic number.

1990933978 is a deficient number, since it is larger than the sum of its proper divisors (1266958022).

1990933978 is a wasteful number, since it uses less digits than its factorization.

1990933978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90497012.

The product of its (nonzero) digits is 3306744, while the sum is 58.

The square root of 1990933978 is about 44619.8832136526. The cubic root of 1990933978 is about 1258.0144207365.

The spelling of 1990933978 in words is "one billion, nine hundred ninety million, nine hundred thirty-three thousand, nine hundred seventy-eight".