71231639 has 2 divisors, whose sum is σ = 71231640. Its totient is φ = 71231638.

The previous prime is 71231617. The next prime is 71231663. The reversal of 71231639 is 93613217.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (93613217) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71231639 - 2¹² = 71227543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71231669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35615819 + 35615820.

It is an arithmetic number, because the mean of its divisors is an integer number (35615820).

Almost surely, 2^71231639 is an apocalyptic number.

71231639 is a deficient number, since it is larger than the sum of its proper divisors (1).

71231639 is an equidigital number, since it uses as much as digits as its factorization.

71231639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6804, while the sum is 32.

The square root of 71231639 is about 8439.8838262147. The cubic root of 71231639 is about 414.5316029516.

The spelling of 71231639 in words is "seventy-one million, two hundred thirty-one thousand, six hundred thirty-nine".