49131391 has 4 divisors (see below), whose sum is σ = 49265632. Its totient is φ = 48997152.

The previous prime is 49131389. The next prime is 49131421. The reversal of 49131391 is 19313194.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 49131391 - 2¹ = 49131389 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 (49131791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66570 + ... + 67303.

It is an arithmetic number, because the mean of its divisors is an integer number (12316408).

Almost surely, 2^49131391 is an apocalyptic number.

49131391 is a deficient number, since it is larger than the sum of its proper divisors (134241).

49131391 is a wasteful number, since it uses less digits than its factorization.

49131391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134240.

The product of its digits is 2916, while the sum is 31.

The square root of 49131391 is about 7009.3787884519. The cubic root of 49131391 is about 366.2573538110.

The spelling of 49131391 in words is "forty-nine million, one hundred thirty-one thousand, three hundred ninety-one".