868385551 has 16 divisors (see below), whose sum is σ = 1008294048. Its totient is φ = 739123200.

The previous prime is 868385533. The next prime is 868385563. The reversal of 868385551 is 155583868.

It is a happy number.

It is a 13-Lehmer number, since φ(868385551) divides (868385551-1)¹³.

It is a cyclic number.

It is not a de Polignac number, because 868385551 - 2¹⁵ = 868352783 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 868385495 and 868385504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (868385521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24061 + ... + 48121.

It is an arithmetic number, because the mean of its divisors is an integer number (63018378).

Almost surely, 2^868385551 is an apocalyptic number.

868385551 is the 24061-st pentagonal number.

868385551 is a deficient number, since it is larger than the sum of its proper divisors (139908497).

868385551 is a wasteful number, since it uses less digits than its factorization.

868385551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24282.

The product of its digits is 1152000, while the sum is 49.

The square root of 868385551 is about 29468.3822257008. The cubic root of 868385551 is about 954.0494003019.

The spelling of 868385551 in words is "eight hundred sixty-eight million, three hundred eighty-five thousand, five hundred fifty-one".