81124219 has 4 divisors (see below), whose sum is σ = 88499160. Its totient is φ = 73749280.

The previous prime is 81124217. The next prime is 81124229. The reversal of 81124219 is 91242118.

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

It is not a de Polignac number, because 81124219 - 2¹ = 81124217 is a prime.

It is a super-2 number, since 2×81124219² = 13162277816719922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81124217) 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, 3687454 + ... + 3687475.

It is an arithmetic number, because the mean of its divisors is an integer number (22124790).

Almost surely, 2^81124219 is an apocalyptic number.

81124219 is a deficient number, since it is larger than the sum of its proper divisors (7374941).

81124219 is a wasteful number, since it uses less digits than its factorization.

81124219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7374940.

The product of its digits is 1152, while the sum is 28.

The square root of 81124219 is about 9006.8984117731. The cubic root of 81124219 is about 432.8959368889.

The spelling of 81124219 in words is "eighty-one million, one hundred twenty-four thousand, two hundred nineteen".