40391289 has 12 divisors (see below), whose sum is σ = 60879936. Its totient is φ = 25756632.

The previous prime is 40391257. The next prime is 40391311. The reversal of 40391289 is 98219304.

It is not a de Polignac number, because 40391289 - 2⁵ = 40391257 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (40391389) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 97357 + ... + 97770.

It is an arithmetic number, because the mean of its divisors is an integer number (5073328).

Almost surely, 2^40391289 is an apocalyptic number.

It is an amenable number.

40391289 is a deficient number, since it is larger than the sum of its proper divisors (20488647).

40391289 is a wasteful number, since it uses less digits than its factorization.

40391289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195156 (or 195153 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 40391289 is about 6355.4141485823. The cubic root of 40391289 is about 343.1067306904.

The spelling of 40391289 in words is "forty million, three hundred ninety-one thousand, two hundred eighty-nine".