84135881 has 2 divisors, whose sum is σ = 84135882. Its totient is φ = 84135880.

The previous prime is 84135847. The next prime is 84135899. The reversal of 84135881 is 18853148.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55950400 + 28185481 = 7480^2 + 5309^2 .

It is a cyclic number.

It is not a de Polignac number, because 84135881 - 2¹⁰ = 84134857 is a prime.

It is a super-2 number, since 2×84135881² = 14157692943292322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (84131881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42067940 + 42067941.

It is an arithmetic number, because the mean of its divisors is an integer number (42067941).

Almost surely, 2^84135881 is an apocalyptic number.

It is an amenable number.

84135881 is a deficient number, since it is larger than the sum of its proper divisors (1).

84135881 is an equidigital number, since it uses as much as digits as its factorization.

84135881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30720, while the sum is 38.

The square root of 84135881 is about 9172.5613107790. The cubic root of 84135881 is about 438.1879349601.

The spelling of 84135881 in words is "eighty-four million, one hundred thirty-five thousand, eight hundred eighty-one".