81149713 has 4 divisors (see below), whose sum is σ = 81647728. Its totient is φ = 80651700.

The previous prime is 81149711. The next prime is 81149749. The reversal of 81149713 is 31794118.

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: 31794118 = 2 ⋅15897059.

It is a cyclic number.

It is not a de Polignac number, because 81149713 - 2¹ = 81149711 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81149711) 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, 248763 + ... + 249088.

It is an arithmetic number, because the mean of its divisors is an integer number (20411932).

Almost surely, 2^81149713 is an apocalyptic number.

It is an amenable number.

81149713 is a deficient number, since it is larger than the sum of its proper divisors (498015).

81149713 is a wasteful number, since it uses less digits than its factorization.

81149713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498014.

The product of its digits is 6048, while the sum is 34.

The square root of 81149713 is about 9008.3135491611. The cubic root of 81149713 is about 432.9412792592.

The spelling of 81149713 in words is "eighty-one million, one hundred forty-nine thousand, seven hundred thirteen".