71642569 has 2 divisors, whose sum is σ = 71642570. Its totient is φ = 71642568.

The previous prime is 71642567. The next prime is 71642611. The reversal of 71642569 is 96524617.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46512400 + 25130169 = 6820^2 + 5013^2 .

It is a cyclic number.

It is not a de Polignac number, because 71642569 - 2¹ = 71642567 is a prime.

It is a super-2 number, since 2×71642569² = 10265315385839522, which contains 22 as substring.

Together with 71642567, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (71642561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35821284 + 35821285.

It is an arithmetic number, because the mean of its divisors is an integer number (35821285).

Almost surely, 2^71642569 is an apocalyptic number.

It is an amenable number.

71642569 is a deficient number, since it is larger than the sum of its proper divisors (1).

71642569 is an equidigital number, since it uses as much as digits as its factorization.

71642569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 40.

The square root of 71642569 is about 8464.1933460903. The cubic root of 71642569 is about 415.3272089190.

The spelling of 71642569 in words is "seventy-one million, six hundred forty-two thousand, five hundred sixty-nine".