71955421 has 2 divisors, whose sum is σ = 71955422. Its totient is φ = 71955420.

The previous prime is 71955419. The next prime is 71955427. The reversal of 71955421 is 12455917.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66243321 + 5712100 = 8139^2 + 2390^2 .

It is a cyclic number.

It is not a de Polignac number, because 71955421 - 2¹ = 71955419 is a prime.

It is a super-2 number, since 2×71955421² = 10355165222574482, which contains 22 as substring.

Together with 71955419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71955427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35977710 + 35977711.

It is an arithmetic number, because the mean of its divisors is an integer number (35977711).

Almost surely, 2^71955421 is an apocalyptic number.

It is an amenable number.

71955421 is a deficient number, since it is larger than the sum of its proper divisors (1).

71955421 is an equidigital number, since it uses as much as digits as its factorization.

71955421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12600, while the sum is 34.

The square root of 71955421 is about 8482.6541247419. The cubic root of 71955421 is about 415.9308875725.

The spelling of 71955421 in words is "seventy-one million, nine hundred fifty-five thousand, four hundred twenty-one".