71820887 has 4 divisors (see below), whose sum is σ = 71947680. Its totient is φ = 71694096.

The previous prime is 71820871. The next prime is 71820901. The reversal of 71820887 is 78802817.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78802817 = 379 ⋅207923.

It is a cyclic number.

It is not a de Polignac number, because 71820887 - 2⁴ = 71820871 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 (71820857) 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, 62543 + ... + 63680.

It is an arithmetic number, because the mean of its divisors is an integer number (17986920).

Almost surely, 2^71820887 is an apocalyptic number.

71820887 is a deficient number, since it is larger than the sum of its proper divisors (126793).

71820887 is a wasteful number, since it uses less digits than its factorization.

71820887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126792.

The product of its (nonzero) digits is 50176, while the sum is 41.

The square root of 71820887 is about 8474.7204673665. The cubic root of 71820887 is about 415.6715058821.

The spelling of 71820887 in words is "seventy-one million, eight hundred twenty thousand, eight hundred eighty-seven".