86870981 has 2 divisors, whose sum is σ = 86870982. Its totient is φ = 86870980.

The previous prime is 86870963. The next prime is 86870989. The reversal of 86870981 is 18907868.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83429956 + 3441025 = 9134^2 + 1855^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-86870981 is a prime.

It is a super-2 number, since 2×86870981² = 15093134679804722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (86870989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43435490 + 43435491.

It is an arithmetic number, because the mean of its divisors is an integer number (43435491).

Almost surely, 2^86870981 is an apocalyptic number.

It is an amenable number.

86870981 is a deficient number, since it is larger than the sum of its proper divisors (1).

86870981 is an equidigital number, since it uses as much as digits as its factorization.

86870981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 193536, while the sum is 47.

The square root of 86870981 is about 9320.4603427084. The cubic root of 86870981 is about 442.8856157453.

The spelling of 86870981 in words is "eighty-six million, eight hundred seventy thousand, nine hundred eighty-one".