71866397 has 4 divisors (see below), whose sum is σ = 72022080. Its totient is φ = 71710716.

The previous prime is 71866393. The next prime is 71866409. The reversal of 71866397 is 79366817.

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 not a de Polignac number, because 71866397 - 2² = 71866393 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 (71866391) 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, 77147 + ... + 78072.

It is an arithmetic number, because the mean of its divisors is an integer number (18005520).

Almost surely, 2^71866397 is an apocalyptic number.

It is an amenable number.

71866397 is a deficient number, since it is larger than the sum of its proper divisors (155683).

71866397 is a wasteful number, since it uses less digits than its factorization.

71866397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155682.

The product of its digits is 381024, while the sum is 47.

The square root of 71866397 is about 8477.4050864637. The cubic root of 71866397 is about 415.7592854345.

The spelling of 71866397 in words is "seventy-one million, eight hundred sixty-six thousand, three hundred ninety-seven".