861087551 has 8 divisors (see below), whose sum is σ = 874609200. Its totient is φ = 847585728.

The previous prime is 861087541. The next prime is 861087583. The reversal of 861087551 is 155780168.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861087551 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 861087499 and 861087508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861087541) 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, 99635 + ... + 107931.

It is an arithmetic number, because the mean of its divisors is an integer number (109326150).

Almost surely, 2^861087551 is an apocalyptic number.

861087551 is a deficient number, since it is larger than the sum of its proper divisors (13521649).

861087551 is a wasteful number, since it uses less digits than its factorization.

861087551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9913.

The product of its (nonzero) digits is 67200, while the sum is 41.

The square root of 861087551 is about 29344.2933293681. The cubic root of 861087551 is about 951.3692355442.

The spelling of 861087551 in words is "eight hundred sixty-one million, eighty-seven thousand, five hundred fifty-one".