918190921 has 8 divisors (see below), whose sum is σ = 942663744. Its totient is φ = 893982960.

The previous prime is 918190913. The next prime is 918190937. The reversal of 918190921 is 129091819.

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 918190921 - 2³ = 918190913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (918190901) 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, 59181 + ... + 73066.

It is an arithmetic number, because the mean of its divisors is an integer number (117832968).

Almost surely, 2^918190921 is an apocalyptic number.

It is an amenable number.

918190921 is a deficient number, since it is larger than the sum of its proper divisors (24472823).

918190921 is a wasteful number, since it uses less digits than its factorization.

918190921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132431.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 918190921 is about 30301.6653172726. The cubic root of 918190921 is about 971.9509115218.

The spelling of 918190921 in words is "nine hundred eighteen million, one hundred ninety thousand, nine hundred twenty-one".