81461043619 has 4 divisors (see below), whose sum is σ = 82998044496. Its totient is φ = 79924042744.

The previous prime is 81461043613. The next prime is 81461043623. The reversal of 81461043619 is 91634016418.

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

It is a cyclic number.

It is not a de Polignac number, because 81461043619 - 2¹⁹ = 81460519331 is a prime.

It is a super-2 number, since 2×81461043619² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81461043613) 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, 768500359 + ... + 768500464.

It is an arithmetic number, because the mean of its divisors is an integer number (20749511124).

Almost surely, 2^81461043619 is an apocalyptic number.

81461043619 is a deficient number, since it is larger than the sum of its proper divisors (1537000877).

81461043619 is a wasteful number, since it uses less digits than its factorization.

81461043619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1537000876.

The product of its (nonzero) digits is 124416, while the sum is 43.

The spelling of 81461043619 in words is "eighty-one billion, four hundred sixty-one million, forty-three thousand, six hundred nineteen".