71825981 has 2 divisors, whose sum is σ = 71825982. Its totient is φ = 71825980.

The previous prime is 71825933. The next prime is 71825983. The reversal of 71825981 is 18952817.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69989956 + 1836025 = 8366^2 + 1355^2 .

It is a cyclic number.

It is not a de Polignac number, because 71825981 - 2¹⁰ = 71824957 is a prime.

It is a super-2 number, since 2×71825981² = 10317943093224722, which contains 22 as substring.

Together with 71825983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71825983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35912990 + 35912991.

It is an arithmetic number, because the mean of its divisors is an integer number (35912991).

Almost surely, 2^71825981 is an apocalyptic number.

It is an amenable number.

71825981 is a deficient number, since it is larger than the sum of its proper divisors (1).

71825981 is an equidigital number, since it uses as much as digits as its factorization.

71825981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 41.

The square root of 71825981 is about 8475.0210029238. The cubic root of 71825981 is about 415.6813330168.

The spelling of 71825981 in words is "seventy-one million, eight hundred twenty-five thousand, nine hundred eighty-one".