71121531 has 16 divisors (see below), whose sum is σ = 102652704. Its totient is φ = 43540224.

The previous prime is 71121529. The next prime is 71121553. The reversal of 71121531 is 13512117.

It is a happy number.

It is not a de Polignac number, because 71121531 - 2¹ = 71121529 is a prime.

It is a super-2 number, since 2×71121531² = 10116544343567922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 71121498 and 71121507.

It is not an unprimeable number, because it can be changed into a prime (71121571) 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, 3055 + ... + 12311.

It is an arithmetic number, because the mean of its divisors is an integer number (6415794).

Almost surely, 2^71121531 is an apocalyptic number.

71121531 is a deficient number, since it is larger than the sum of its proper divisors (31531173).

71121531 is a wasteful number, since it uses less digits than its factorization.

71121531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9470.

The product of its digits is 210, while the sum is 21.

The square root of 71121531 is about 8433.3582278947. The cubic root of 71121531 is about 414.3179021081.

Adding to 71121531 its reverse (13512117), we get a palindrome (84633648).

The spelling of 71121531 in words is "seventy-one million, one hundred twenty-one thousand, five hundred thirty-one".