81537749629 has 8 divisors (see below), whose sum is σ = 94146680768. Its totient is φ = 69168988800.

The previous prime is 81537749591. The next prime is 81537749651. The reversal of 81537749629 is 92694773518.

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 81537749629 - 2¹³ = 81537741437 is a prime.

It is a super-2 number, since 2×81537749629² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81537749669) 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, 60041847 + ... + 60043204.

It is an arithmetic number, because the mean of its divisors is an integer number (11768335096).

Almost surely, 2^81537749629 is an apocalyptic number.

It is an amenable number.

81537749629 is a deficient number, since it is larger than the sum of its proper divisors (12608931139).

81537749629 is a wasteful number, since it uses less digits than its factorization.

81537749629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120085155.

The product of its digits is 22861440, while the sum is 61.

The spelling of 81537749629 in words is "eighty-one billion, five hundred thirty-seven million, seven hundred forty-nine thousand, six hundred twenty-nine".