81129424615 has 32 divisors (see below), whose sum is σ = 105891001920. Its totient is φ = 59432239104.

The previous prime is 81129424589. The next prime is 81129424711. The reversal of 81129424615 is 51642492118.

It is a cyclic number.

It is not a de Polignac number, because 81129424615 - 2⁷ = 81129424487 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 896151 + ... + 982519.

It is an arithmetic number, because the mean of its divisors is an integer number (3309093810).

Almost surely, 2^81129424615 is an apocalyptic number.

81129424615 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81129424615 is a deficient number, since it is larger than the sum of its proper divisors (24761577305).

81129424615 is a wasteful number, since it uses less digits than its factorization.

81129424615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86691.

The product of its digits is 138240, while the sum is 43.

The spelling of 81129424615 in words is "eighty-one billion, one hundred twenty-nine million, four hundred twenty-four thousand, six hundred fifteen".