81419964 has 12 divisors (see below), whose sum is σ = 189979944. Its totient is φ = 27139984.

The previous prime is 81419951. The next prime is 81419969. The reversal of 81419964 is 46991418.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×81419964² = 13258421075522592, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81419969) 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, 3392487 + ... + 3392510.

It is an arithmetic number, because the mean of its divisors is an integer number (15831662).

Almost surely, 2^81419964 is an apocalyptic number.

It is an amenable number.

81419964 is an abundant number, since it is smaller than the sum of its proper divisors (108559980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81419964 is a wasteful number, since it uses less digits than its factorization.

81419964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6785004 (or 6785002 counting only the distinct ones).

The product of its digits is 62208, while the sum is 42.

The square root of 81419964 is about 9023.3011697494. The cubic root of 81419964 is about 433.4213514829.

The spelling of 81419964 in words is "eighty-one million, four hundred nineteen thousand, nine hundred sixty-four".