71721863 has 2 divisors, whose sum is σ = 71721864. Its totient is φ = 71721862.

The previous prime is 71721847. The next prime is 71721869. The reversal of 71721863 is 36812717.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 71721863 - 2⁴ = 71721847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71721869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35860931 + 35860932.

It is an arithmetic number, because the mean of its divisors is an integer number (35860932).

Almost surely, 2^71721863 is an apocalyptic number.

71721863 is a deficient number, since it is larger than the sum of its proper divisors (1).

71721863 is an equidigital number, since it uses as much as digits as its factorization.

71721863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14112, while the sum is 35.

The square root of 71721863 is about 8468.8761355920. The cubic root of 71721863 is about 415.4803804833.

The spelling of 71721863 in words is "seventy-one million, seven hundred twenty-one thousand, eight hundred sixty-three".