842661391 has 16 divisors (see below), whose sum is σ = 992402208. Its totient is φ = 705398400.

The previous prime is 842661367. The next prime is 842661431. The reversal of 842661391 is 193166248.

It is a cyclic number.

It is not a de Polignac number, because 842661391 - 2⁵ = 842661359 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 (842661301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53205 + ... + 67201.

It is an arithmetic number, because the mean of its divisors is an integer number (62025138).

Almost surely, 2^842661391 is an apocalyptic number.

842661391 is a deficient number, since it is larger than the sum of its proper divisors (149740817).

842661391 is a wasteful number, since it uses less digits than its factorization.

842661391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14442.

The product of its digits is 62208, while the sum is 40.

The square root of 842661391 is about 29028.6305395208. The cubic root of 842661391 is about 944.5342239599.

The spelling of 842661391 in words is "eight hundred forty-two million, six hundred sixty-one thousand, three hundred ninety-one".