801649861 has 4 divisors (see below), whose sum is σ = 814791724. Its totient is φ = 788508000.

The previous prime is 801649847. The next prime is 801649867. The reversal of 801649861 is 168946108.

801649861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 341547361 + 460102500 = 18481^2 + 21450^2 .

It is a cyclic number.

It is not a de Polignac number, because 801649861 - 2⁵ = 801649829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (801649867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6570840 + ... + 6570961.

It is an arithmetic number, because the mean of its divisors is an integer number (203697931).

Almost surely, 2^801649861 is an apocalyptic number.

It is an amenable number.

801649861 is a deficient number, since it is larger than the sum of its proper divisors (13141863).

801649861 is a wasteful number, since it uses less digits than its factorization.

801649861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13141862.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 801649861 is about 28313.4219231798. The cubic root of 801649861 is about 928.9554932228.

The spelling of 801649861 in words is "eight hundred one million, six hundred forty-nine thousand, eight hundred sixty-one".