91021012123 has 8 divisors (see below), whose sum is σ = 92519760960. Its totient is φ = 89526387720.

The previous prime is 91021012073. The next prime is 91021012127. The reversal of 91021012123 is 32121012019.

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

It is a cyclic number.

It is not a de Polignac number, because 91021012123 - 2⁹ = 91021011611 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91021012094 and 91021012103.

It is not an unprimeable number, because it can be changed into a prime (91021012127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 986593 + ... + 1074898.

It is an arithmetic number, because the mean of its divisors is an integer number (11564970120).

Almost surely, 2^91021012123 is an apocalyptic number.

91021012123 is a deficient number, since it is larger than the sum of its proper divisors (1498748837).

91021012123 is a wasteful number, since it uses less digits than its factorization.

91021012123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2062217.

The product of its (nonzero) digits is 216, while the sum is 22.

The spelling of 91021012123 in words is "ninety-one billion, twenty-one million, twelve thousand, one hundred twenty-three".