81219411 has 72 divisors (see below), whose sum is σ = 152041344. Its totient is φ = 41368320.

The previous prime is 81219409. The next prime is 81219419. The reversal of 81219411 is 11491218.

It is not a de Polignac number, because 81219411 - 2¹ = 81219409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81219419) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 177495 + ... + 177951.

Almost surely, 2^81219411 is an apocalyptic number.

81219411 is a deficient number, since it is larger than the sum of its proper divisors (70821933).

81219411 is a wasteful number, since it uses less digits than its factorization.

81219411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521 (or 511 counting only the distinct ones).

The product of its digits is 576, while the sum is 27.

The square root of 81219411 is about 9012.1812564994. The cubic root of 81219411 is about 433.0651922316.

The spelling of 81219411 in words is "eighty-one million, two hundred nineteen thousand, four hundred eleven".