71531945 has 8 divisors (see below), whose sum is σ = 86353344. Its totient is φ = 56882224.

The previous prime is 71531939. The next prime is 71531953. The reversal of 71531945 is 54913517.

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

It is a cyclic number.

It is not a de Polignac number, because 71531945 - 2¹² = 71527849 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41999 + ... + 43668.

It is an arithmetic number, because the mean of its divisors is an integer number (10794168).

Almost surely, 2^71531945 is an apocalyptic number.

It is an amenable number.

71531945 is a deficient number, since it is larger than the sum of its proper divisors (14821399).

71531945 is a wasteful number, since it uses less digits than its factorization.

71531945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85839.

The product of its digits is 18900, while the sum is 35.

The square root of 71531945 is about 8457.6559991525. The cubic root of 71531945 is about 415.1133285113.

The spelling of 71531945 in words is "seventy-one million, five hundred thirty-one thousand, nine hundred forty-five".