1991509058 has 48 divisors (see below), whose sum is σ = 3842969184. Its totient is φ = 765253440.

The previous prime is 1991509057. The next prime is 1991509063. The reversal of 1991509058 is 8509051991.

It is a super-2 number, since 2×1991509058² = 7932216656192094728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1991509057) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 66041 + ... + 91347.

It is an arithmetic number, because the mean of its divisors is an integer number (80061858).

Almost surely, 2^1991509058 is an apocalyptic number.

1991509058 is a deficient number, since it is larger than the sum of its proper divisors (1851460126).

1991509058 is a wasteful number, since it uses less digits than its factorization.

1991509058 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25407 (or 25400 counting only the distinct ones).

The product of its (nonzero) digits is 145800, while the sum is 47.

The square root of 1991509058 is about 44626.3269606630. The cubic root of 1991509058 is about 1258.1355346283.

The spelling of 1991509058 in words is "one billion, nine hundred ninety-one million, five hundred nine thousand, fifty-eight".