71951921 has 2 divisors, whose sum is σ = 71951922. Its totient is φ = 71951920.

The previous prime is 71951909. The next prime is 71951927. The reversal of 71951921 is 12915917.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62410000 + 9541921 = 7900^2 + 3089^2 .

It is a cyclic number.

It is not a de Polignac number, because 71951921 - 2¹⁰ = 71950897 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (71951927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35975960 + 35975961.

It is an arithmetic number, because the mean of its divisors is an integer number (35975961).

Almost surely, 2^71951921 is an apocalyptic number.

It is an amenable number.

71951921 is a deficient number, since it is larger than the sum of its proper divisors (1).

71951921 is an equidigital number, since it uses as much as digits as its factorization.

71951921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5670, while the sum is 35.

The square root of 71951921 is about 8482.4478188787. The cubic root of 71951921 is about 415.9241436668.

The spelling of 71951921 in words is "seventy-one million, nine hundred fifty-one thousand, nine hundred twenty-one".