868135021 has 8 divisors (see below), whose sum is σ = 935212824. Its totient is φ = 801099840.

The previous prime is 868134997. The next prime is 868135031. The reversal of 868135021 is 120531868.

It can be written as a sum of positive squares in 4 ways, for example, as 27772900 + 840362121 = 5270^2 + 28989^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 868135021 - 2⁵ = 868134989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (868135031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40935 + ... + 58411.

It is an arithmetic number, because the mean of its divisors is an integer number (116901603).

Almost surely, 2^868135021 is an apocalyptic number.

It is an amenable number.

868135021 is a deficient number, since it is larger than the sum of its proper divisors (67077803).

868135021 is a wasteful number, since it uses less digits than its factorization.

868135021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21311.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 868135021 is about 29464.1310918887. The cubic root of 868135021 is about 953.9576434452.

Adding to 868135021 its reverse (120531868), we get a palindrome (988666889).

The spelling of 868135021 in words is "eight hundred sixty-eight million, one hundred thirty-five thousand, twenty-one".