81863419 has 8 divisors (see below), whose sum is σ = 94006080. Its totient is φ = 70504200.

The previous prime is 81863407. The next prime is 81863437. The reversal of 81863419 is 91436818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81863419 - 2¹³ = 81855227 is a prime.

It is a super-2 number, since 2×81863419² = 13403238740739122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81863489) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195637 + ... + 196054.

It is an arithmetic number, because the mean of its divisors is an integer number (11750760).

Almost surely, 2^81863419 is an apocalyptic number.

81863419 is a deficient number, since it is larger than the sum of its proper divisors (12142661).

81863419 is a wasteful number, since it uses less digits than its factorization.

81863419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391721.

The product of its digits is 41472, while the sum is 40.

The square root of 81863419 is about 9047.8405710976. The cubic root of 81863419 is about 434.2068057409.

The spelling of 81863419 in words is "eighty-one million, eight hundred sixty-three thousand, four hundred nineteen".