81876545 has 4 divisors (see below), whose sum is σ = 98251860. Its totient is φ = 65501232.

The previous prime is 81876499. The next prime is 81876551. The reversal of 81876545 is 54567818.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 23001616 + 58874929 = 4796^2 + 7673^2 .

It is a cyclic number.

It is not a de Polignac number, because 81876545 - 2²⁴ = 65099329 is a prime.

It is a super-2 number, since 2×81876545² = 13407537242274050, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 81876496 and 81876505.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8187650 + ... + 8187659.

It is an arithmetic number, because the mean of its divisors is an integer number (24562965).

Almost surely, 2^81876545 is an apocalyptic number.

It is an amenable number.

81876545 is a deficient number, since it is larger than the sum of its proper divisors (16375315).

81876545 is a wasteful number, since it uses less digits than its factorization.

81876545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16375314.

The product of its digits is 268800, while the sum is 44.

The square root of 81876545 is about 9048.5659084741. The cubic root of 81876545 is about 434.2300114414.

The spelling of 81876545 in words is "eighty-one million, eight hundred seventy-six thousand, five hundred forty-five".