86429209721 has 12 divisors (see below), whose sum is σ = 91588101108. Its totient is φ = 81538896384.

The previous prime is 86429209709. The next prime is 86429209729. The reversal of 86429209721 is 12790292468.

It can be written as a sum of positive squares in 2 ways, for example, as 54574099321 + 31855110400 = 233611^2 + 178480^2 .

It is a de Polignac number, because none of the positive numbers 2^k-86429209721 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 86429209721.

It is not an unprimeable number, because it can be changed into a prime (86429209729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1080440 + ... + 1157673.

It is an arithmetic number, because the mean of its divisors is an integer number (7632341759).

Almost surely, 2^86429209721 is an apocalyptic number.

It is an amenable number.

86429209721 is a deficient number, since it is larger than the sum of its proper divisors (5158891387).

86429209721 is a wasteful number, since it uses less digits than its factorization.

86429209721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2238232 (or 2238209 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 50.

The spelling of 86429209721 in words is "eighty-six billion, four hundred twenty-nine million, two hundred nine thousand, seven hundred twenty-one".