81540213542 has 8 divisors (see below), whose sum is σ = 122338074600. Its totient is φ = 40760855344.

The previous prime is 81540213541. The next prime is 81540213551. The reversal of 81540213542 is 24531204518.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81540213541) 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, 4614692 + ... + 4632327.

It is an arithmetic number, because the mean of its divisors is an integer number (15292259325).

Almost surely, 2^81540213542 is an apocalyptic number.

81540213542 is a deficient number, since it is larger than the sum of its proper divisors (40797861058).

81540213542 is a wasteful number, since it uses less digits than its factorization.

81540213542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9251430.

The product of its (nonzero) digits is 38400, while the sum is 35.

The spelling of 81540213542 in words is "eighty-one billion, five hundred forty million, two hundred thirteen thousand, five hundred forty-two".