9899779990 has 32 divisors (see below), whose sum is σ = 17897158656. Its totient is φ = 3942708960.

The previous prime is 9899779961. The next prime is 9899780003. The reversal of 9899779990 is 999779989.

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, 4797699 + ... + 4799761.

It is an arithmetic number, because the mean of its divisors is an integer number (559286208).

Almost surely, 2^9899779990 is an apocalyptic number.

9899779990 is a deficient number, since it is larger than the sum of its proper divisors (7997378666).

9899779990 is a wasteful number, since it uses less digits than its factorization.

9899779990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3924.

The product of its (nonzero) digits is 208324872, while the sum is 76.

The square root of 9899779990 is about 99497.6381126708. The cubic root of 9899779990 is about 2147.2132627769.

The spelling of 9899779990 in words is "nine billion, eight hundred ninety-nine million, seven hundred seventy-nine thousand, nine hundred ninety".