857144991 has 16 divisors (see below), whose sum is σ = 1165713120. Its totient is φ = 560027520.

The previous prime is 857144983. The next prime is 857144993. The reversal of 857144991 is 199441758.

It is not a de Polignac number, because 857144991 - 2³ = 857144983 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 857144991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857144993) 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, 173901 + ... + 178761.

It is an arithmetic number, because the mean of its divisors is an integer number (72857070).

Almost surely, 2^857144991 is an apocalyptic number.

857144991 is a deficient number, since it is larger than the sum of its proper divisors (308568129).

857144991 is a wasteful number, since it uses less digits than its factorization.

857144991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6026.

The product of its digits is 362880, while the sum is 48.

The square root of 857144991 is about 29277.0386309818. The cubic root of 857144991 is about 949.9150398629.

The spelling of 857144991 in words is "eight hundred fifty-seven million, one hundred forty-four thousand, nine hundred ninety-one".