71999281 has 4 divisors (see below), whose sum is σ = 73357812. Its totient is φ = 70640752.

The previous prime is 71999273. The next prime is 71999287. The reversal of 71999281 is 18299917.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18299917 = 797 ⋅22961.

It can be written as a sum of positive squares in 2 ways, for example, as 52998400 + 19000881 = 7280^2 + 4359^2 .

It is a cyclic number.

It is not a de Polignac number, because 71999281 - 2³ = 71999273 is a prime.

It is a super-2 number, since 2×71999281² = 10367792929033922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71999287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 679186 + ... + 679291.

It is an arithmetic number, because the mean of its divisors is an integer number (18339453).

Almost surely, 2^71999281 is an apocalyptic number.

It is an amenable number.

71999281 is a deficient number, since it is larger than the sum of its proper divisors (1358531).

71999281 is a wasteful number, since it uses less digits than its factorization.

71999281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1358530.

The product of its digits is 81648, while the sum is 46.

The square root of 71999281 is about 8485.2390066515. The cubic root of 71999281 is about 416.0153798092.

It can be divided in two parts, 719 and 99281, that added together give a 5-th power (100000 = 10⁵).

The spelling of 71999281 in words is "seventy-one million, nine hundred ninety-nine thousand, two hundred eighty-one".