71642665 has 4 divisors (see below), whose sum is σ = 85971204. Its totient is φ = 57314128.

The previous prime is 71642663. The next prime is 71642699. The reversal of 71642665 is 56624617.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17884441 + 53758224 = 4229^2 + 7332^2 .

It is a cyclic number.

It is not a de Polignac number, because 71642665 - 2¹ = 71642663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71642663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7164262 + ... + 7164271.

It is an arithmetic number, because the mean of its divisors is an integer number (21492801).

Almost surely, 2^71642665 is an apocalyptic number.

It is an amenable number.

71642665 is a deficient number, since it is larger than the sum of its proper divisors (14328539).

71642665 is a wasteful number, since it uses less digits than its factorization.

71642665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14328538.

The product of its digits is 60480, while the sum is 37.

The square root of 71642665 is about 8464.1990170364. The cubic root of 71642665 is about 415.3273944297.

The spelling of 71642665 in words is "seventy-one million, six hundred forty-two thousand, six hundred sixty-five".