71679991 has 2 divisors, whose sum is σ = 71679992. Its totient is φ = 71679990.

The previous prime is 71679961. The next prime is 71680031. The reversal of 71679991 is 19997617.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 71679991 - 2¹³ = 71671799 is a prime.

It is a super-2 number, since 2×71679991² = 10276042219520162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71679901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35839995 + 35839996.

It is an arithmetic number, because the mean of its divisors is an integer number (35839996).

Almost surely, 2^71679991 is an apocalyptic number.

71679991 is a deficient number, since it is larger than the sum of its proper divisors (1).

71679991 is an equidigital number, since it uses as much as digits as its factorization.

71679991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 214326, while the sum is 49.

The square root of 71679991 is about 8466.4036638941. The cubic root of 71679991 is about 415.3995107625.

The spelling of 71679991 in words is "seventy-one million, six hundred seventy-nine thousand, nine hundred ninety-one".