71916421 has 2 divisors, whose sum is σ = 71916422. Its totient is φ = 71916420.

The previous prime is 71916391. The next prime is 71916451. The reversal of 71916421 is 12461917.

It is a balanced prime because it is at equal distance from previous prime (71916391) and next prime (71916451).

It can be written as a sum of positive squares in only one way, i.e., 37822500 + 34093921 = 6150^2 + 5839^2 .

It is a cyclic number.

It is not a de Polignac number, because 71916421 - 2¹³ = 71908229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71916451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35958210 + 35958211.

It is an arithmetic number, because the mean of its divisors is an integer number (35958211).

Almost surely, 2^71916421 is an apocalyptic number.

It is an amenable number.

71916421 is a deficient number, since it is larger than the sum of its proper divisors (1).

71916421 is an equidigital number, since it uses as much as digits as its factorization.

71916421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 31.

The square root of 71916421 is about 8480.3550043616. The cubic root of 71916421 is about 415.8557288333.

The spelling of 71916421 in words is "seventy-one million, nine hundred sixteen thousand, four hundred twenty-one".