82400923781 has 4 divisors (see below), whose sum is σ = 89891916864. Its totient is φ = 74909930700.

The previous prime is 82400923769. The next prime is 82400923817. The reversal of 82400923781 is 18732900428.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-82400923781 is a prime.

It is a super-3 number, since 3×82400923781³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82400023781) 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, 3745496525 + ... + 3745496546.

It is an arithmetic number, because the mean of its divisors is an integer number (22472979216).

Almost surely, 2^82400923781 is an apocalyptic number.

It is an amenable number.

82400923781 is a deficient number, since it is larger than the sum of its proper divisors (7490993083).

82400923781 is a wasteful number, since it uses less digits than its factorization.

82400923781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7490993082.

The product of its (nonzero) digits is 193536, while the sum is 44.

The spelling of 82400923781 in words is "eighty-two billion, four hundred million, nine hundred twenty-three thousand, seven hundred eighty-one".