71561137 has 4 divisors (see below), whose sum is σ = 71648496. Its totient is φ = 71473780.

The previous prime is 71561131. The next prime is 71561167. The reversal of 71561137 is 73116517.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71561137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 71561099 and 71561108.

It is not an unprimeable number, because it can be changed into a prime (71561131) 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, 42439 + ... + 44092.

It is an arithmetic number, because the mean of its divisors is an integer number (17912124).

Almost surely, 2^71561137 is an apocalyptic number.

It is an amenable number.

71561137 is a deficient number, since it is larger than the sum of its proper divisors (87359).

71561137 is an equidigital number, since it uses as much as digits as its factorization.

71561137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87358.

The product of its digits is 4410, while the sum is 31.

The square root of 71561137 is about 8459.3815967835. The cubic root of 71561137 is about 415.1697897200.

The spelling of 71561137 in words is "seventy-one million, five hundred sixty-one thousand, one hundred thirty-seven".