7161581 has 4 divisors (see below), whose sum is σ = 8184672. Its totient is φ = 6138492.

The previous prime is 7161577. The next prime is 7161599. The reversal of 7161581 is 1851617.

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: 1851617 = 617 ⋅3001.

It is a cyclic number.

It is not a de Polignac number, because 7161581 - 2² = 7161577 is a prime.

It is a super-2 number, since 2×7161581² = 102576484839122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7160581) 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, 511535 + ... + 511548.

It is an arithmetic number, because the mean of its divisors is an integer number (2046168).

Almost surely, 2^7161581 is an apocalyptic number.

It is an amenable number.

7161581 is a deficient number, since it is larger than the sum of its proper divisors (1023091).

7161581 is a wasteful number, since it uses less digits than its factorization.

7161581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1023090.

The product of its digits is 1680, while the sum is 29.

The square root of 7161581 is about 2676.1130394660. The cubic root of 7161581 is about 192.7538092459.

The spelling of 7161581 in words is "seven million, one hundred sixty-one thousand, five hundred eighty-one".