91091091002 has 4 divisors (see below), whose sum is σ = 136636636506. Its totient is φ = 45545545500.

The previous prime is 91091091001. The next prime is 91091091011. The reversal of 91091091002 is 20019019019.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 84716505721 + 6374585281 = 291061^2 + 79841^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 91091091002.

It is not an unprimeable number, because it can be changed into a prime (91091091001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22772772749 + ... + 22772772752.

Almost surely, 2^91091091002 is an apocalyptic number.

91091091002 is a deficient number, since it is larger than the sum of its proper divisors (45545545504).

91091091002 is a wasteful number, since it uses less digits than its factorization.

91091091002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45545545503.

The product of its (nonzero) digits is 1458, while the sum is 32.

The spelling of 91091091002 in words is "ninety-one billion, ninety-one million, ninety-one thousand, two".