71918251 has 4 divisors (see below), whose sum is σ = 72183904. Its totient is φ = 71652600.

The previous prime is 71918239. The next prime is 71918257. The reversal of 71918251 is 15281917.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15281917 = 7 ⋅2183131.

It is a cyclic number.

It is not a de Polignac number, because 71918251 - 2⁷ = 71918123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71918257) 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, 132420 + ... + 132961.

It is an arithmetic number, because the mean of its divisors is an integer number (18045976).

Almost surely, 2^71918251 is an apocalyptic number.

71918251 is a deficient number, since it is larger than the sum of its proper divisors (265653).

71918251 is a wasteful number, since it uses less digits than its factorization.

71918251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265652.

The product of its digits is 5040, while the sum is 34.

The square root of 71918251 is about 8480.4629001016. The cubic root of 71918251 is about 415.8592561201.

The spelling of 71918251 in words is "seventy-one million, nine hundred eighteen thousand, two hundred fifty-one".