861665454 has 48 divisors (see below), whose sum is σ = 2028407472. Its totient is φ = 262773504.

The previous prime is 861665411. The next prime is 861665459. The reversal of 861665454 is 454566168.

It is a super-2 number, since 2×861665454² = 1484934709234052232, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861665459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10149 + ... + 42735.

It is an arithmetic number, because the mean of its divisors is an integer number (42258489).

Almost surely, 2^861665454 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861665454, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1014203736).

861665454 is an abundant number, since it is smaller than the sum of its proper divisors (1166742018).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

861665454 is a wasteful number, since it uses less digits than its factorization.

861665454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32721 (or 32718 counting only the distinct ones).

The product of its digits is 691200, while the sum is 45.

The square root of 861665454 is about 29354.1386179189. The cubic root of 861665454 is about 951.5820192442.

The spelling of 861665454 in words is "eight hundred sixty-one million, six hundred sixty-five thousand, four hundred fifty-four".