86842709721 has 6 divisors (see below), whose sum is σ = 125439469610. Its totient is φ = 57895139808.

The previous prime is 86842709717. The next prime is 86842709741. The reversal of 86842709721 is 12790724868.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 73446962121 + 13395747600 = 271011^2 + 115740^2 .

It is not a de Polignac number, because 86842709721 - 2² = 86842709717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (86842709741) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4824594976 + ... + 4824594993.

Almost surely, 2^86842709721 is an apocalyptic number.

It is an amenable number.

86842709721 is a deficient number, since it is larger than the sum of its proper divisors (38596759889).

86842709721 is a wasteful number, since it uses less digits than its factorization.

86842709721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9649189975 (or 9649189972 counting only the distinct ones).

The product of its (nonzero) digits is 2709504, while the sum is 54.

The spelling of 86842709721 in words is "eighty-six billion, eight hundred forty-two million, seven hundred nine thousand, seven hundred twenty-one".