71051609 has 4 divisors (see below), whose sum is σ = 72704016. Its totient is φ = 69399204.

The previous prime is 71051587. The next prime is 71051611. The reversal of 71051609 is 90615017.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90615017 = 1669 ⋅54293.

It is a cyclic number.

It is not a de Polignac number, because 71051609 - 2⁸ = 71051353 is a prime.

It is a super-2 number, since 2×71051609² = 10096662282977762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71051689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 826139 + ... + 826224.

It is an arithmetic number, because the mean of its divisors is an integer number (18176004).

Almost surely, 2^71051609 is an apocalyptic number.

It is an amenable number.

71051609 is a deficient number, since it is larger than the sum of its proper divisors (1652407).

71051609 is a wasteful number, since it uses less digits than its factorization.

71051609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1652406.

The product of its (nonzero) digits is 1890, while the sum is 29.

The square root of 71051609 is about 8429.2116475979. The cubic root of 71051609 is about 414.1820809069.

The spelling of 71051609 in words is "seventy-one million, fifty-one thousand, six hundred nine".