81869287740 has 24 divisors (see below), whose sum is σ = 229234005840. Its totient is φ = 21831810048.

The previous prime is 81869287679. The next prime is 81869287741. The reversal of 81869287740 is 4778296818.

It is a Harshad number since it is a multiple of its sum of digits (60), and also a Moran number because the ratio is a prime number: 1364488129 = 81869287740 / (8 + 1 + 8 + 6 + 9 + 2 + 8 + 7 + 7 + 4 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81869287741) 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, 682244005 + ... + 682244124.

It is an arithmetic number, because the mean of its divisors is an integer number (9551416910).

Almost surely, 2^81869287740 is an apocalyptic number.

It is an amenable number.

81869287740 is an abundant number, since it is smaller than the sum of its proper divisors (147364718100).

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

81869287740 is a wasteful number, since it uses less digits than its factorization.

81869287740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1364488141 (or 1364488139 counting only the distinct ones).

The product of its (nonzero) digits is 10838016, while the sum is 60.

The spelling of 81869287740 in words is "eighty-one billion, eight hundred sixty-nine million, two hundred eighty-seven thousand, seven hundred forty".