84257391 has 8 divisors (see below), whose sum is σ = 114020224. Its totient is φ = 55333080.

The previous prime is 84257387. The next prime is 84257413. The reversal of 84257391 is 19375248.

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

It is not a de Polignac number, because 84257391 - 2² = 84257387 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 (84257311) 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, 209395 + ... + 209796.

It is an arithmetic number, because the mean of its divisors is an integer number (14252528).

Almost surely, 2^84257391 is an apocalyptic number.

84257391 is a deficient number, since it is larger than the sum of its proper divisors (29762833).

84257391 is a wasteful number, since it uses less digits than its factorization.

84257391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419261.

The product of its digits is 60480, while the sum is 39.

The square root of 84257391 is about 9179.1824799380. The cubic root of 84257391 is about 438.3987788313.

It can be divided in two parts, 84257 and 391, that added together give a palindrome (84648).

The spelling of 84257391 in words is "eighty-four million, two hundred fifty-seven thousand, three hundred ninety-one".