72171789479 has 2 divisors, whose sum is σ = 72171789480. Its totient is φ = 72171789478.

The previous prime is 72171789439. The next prime is 72171789497. The reversal of 72171789479 is 97498717127.

Together with next prime (72171789497) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 72171789479 - 2¹² = 72171785383 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72171789439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36085894739 + 36085894740.

It is an arithmetic number, because the mean of its divisors is an integer number (36085894740).

Almost surely, 2^72171789479 is an apocalyptic number.

72171789479 is a deficient number, since it is larger than the sum of its proper divisors (1).

72171789479 is an equidigital number, since it uses as much as digits as its factorization.

72171789479 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12446784, while the sum is 62.

The spelling of 72171789479 in words is "seventy-two billion, one hundred seventy-one million, seven hundred eighty-nine thousand, four hundred seventy-nine".