891013201021 has 4 divisors (see below), whose sum is σ = 891387107392. Its totient is φ = 890639294652.

The previous prime is 891013200983. The next prime is 891013201037. The reversal of 891013201021 is 120102310198.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 891013201021 - 2¹¹ = 891013198973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891013201051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 186949611 + ... + 186954376.

It is an arithmetic number, because the mean of its divisors is an integer number (222846776848).

Almost surely, 2^891013201021 is an apocalyptic number.

It is an amenable number.

891013201021 is a deficient number, since it is larger than the sum of its proper divisors (373906371).

891013201021 is a wasteful number, since it uses less digits than its factorization.

891013201021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373906370.

The product of its (nonzero) digits is 864, while the sum is 28.

The spelling of 891013201021 in words is "eight hundred ninety-one billion, thirteen million, two hundred one thousand, twenty-one".