845991021 has 8 divisors (see below), whose sum is σ = 1128597760. Its totient is φ = 563689152.

The previous prime is 845991019. The next prime is 845991059. The reversal of 845991021 is 120199548.

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

It is not a de Polignac number, because 845991021 - 2¹ = 845991019 is a prime.

It is a super-2 number, since 2×845991021² = 1431401615225244882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (845991521) 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, 69661 + ... + 80898.

It is an arithmetic number, because the mean of its divisors is an integer number (141074720).

Almost surely, 2^845991021 is an apocalyptic number.

It is an amenable number.

845991021 is a deficient number, since it is larger than the sum of its proper divisors (282606739).

845991021 is a wasteful number, since it uses less digits than its factorization.

845991021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152435.

The product of its (nonzero) digits is 25920, while the sum is 39.

The square root of 845991021 is about 29085.9247918989. The cubic root of 845991021 is about 945.7766432560.

The spelling of 845991021 in words is "eight hundred forty-five million, nine hundred ninety-one thousand, twenty-one".