991309142 has 16 divisors (see below), whose sum is σ = 1503522432. Its totient is φ = 490147200.

The previous prime is 991309139. The next prime is 991309157. The reversal of 991309142 is 241903199.

It is a junction number, because it is equal to n+sod(n) for n = 991309096 and 991309105.

It is a congruent 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, 194843 + ... + 199865.

It is an arithmetic number, because the mean of its divisors is an integer number (93970152).

Almost surely, 2^991309142 is an apocalyptic number.

991309142 is a deficient number, since it is larger than the sum of its proper divisors (512213290).

991309142 is a wasteful number, since it uses less digits than its factorization.

991309142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6103.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 991309142 is about 31485.0622041628. The cubic root of 991309142 is about 997.0946142420.

The spelling of 991309142 in words is "nine hundred ninety-one million, three hundred nine thousand, one hundred forty-two".