891249539 has 2 divisors, whose sum is σ = 891249540. Its totient is φ = 891249538.

The previous prime is 891249503. The next prime is 891249577. The reversal of 891249539 is 935942198.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-891249539 is a prime.

It is a super-3 number, since 3×891249539³ (a number of 28 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (891249239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445624769 + 445624770.

It is an arithmetic number, because the mean of its divisors is an integer number (445624770).

Almost surely, 2^891249539 is an apocalyptic number.

891249539 is a deficient number, since it is larger than the sum of its proper divisors (1).

891249539 is an equidigital number, since it uses as much as digits as its factorization.

891249539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 50.

The square root of 891249539 is about 29853.8027560979. The cubic root of 891249539 is about 962.3501228145.

The spelling of 891249539 in words is "eight hundred ninety-one million, two hundred forty-nine thousand, five hundred thirty-nine".