71640623 has 4 divisors (see below), whose sum is σ = 73306728. Its totient is φ = 69974520.

The previous prime is 71640587. The next prime is 71640629. The reversal of 71640623 is 32604617.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32604617 = 1831 ⋅17807.

It is a cyclic number.

It is not a de Polignac number, because 71640623 - 2⁶ = 71640559 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 (71640629) 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, 832988 + ... + 833073.

It is an arithmetic number, because the mean of its divisors is an integer number (18326682).

Almost surely, 2^71640623 is an apocalyptic number.

71640623 is a deficient number, since it is larger than the sum of its proper divisors (1666105).

71640623 is a wasteful number, since it uses less digits than its factorization.

71640623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1666104.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 71640623 is about 8464.0783904687. The cubic root of 71640623 is about 415.3234484263.

The spelling of 71640623 in words is "seventy-one million, six hundred forty thousand, six hundred twenty-three".