86720661 has 12 divisors (see below), whose sum is σ = 125580780. Its totient is φ = 57667200.

The previous prime is 86720653. The next prime is 86720681. The reversal of 86720661 is 16602768.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 86378436 + 342225 = 9294^2 + 585^2 .

It is not a de Polignac number, because 86720661 - 2³ = 86720653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86720681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8406 + ... + 15623.

It is an arithmetic number, because the mean of its divisors is an integer number (10465065).

Almost surely, 2^86720661 is an apocalyptic number.

It is an amenable number.

86720661 is a deficient number, since it is larger than the sum of its proper divisors (38860119).

86720661 is a wasteful number, since it uses less digits than its factorization.

86720661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24436 (or 24433 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 86720661 is about 9312.3928718670. The cubic root of 86720661 is about 442.6300144625.

It can be divided in two parts, 867 and 20661, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 86720661 in words is "eighty-six million, seven hundred twenty thousand, six hundred sixty-one".