801866647 has 4 divisors (see below), whose sum is σ = 801937440. Its totient is φ = 801795856.

The previous prime is 801866579. The next prime is 801866651. The reversal of 801866647 is 746668108.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a 4-Lehmer number, since φ(801866647) divides (801866647-1)⁴.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-801866647 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 801866597 and 801866606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (801866447) 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, 14158 + ... + 42475.

It is an arithmetic number, because the mean of its divisors is an integer number (200484360).

It is a Poulet number, since it divides 2^801866646-1.

Almost surely, 2^801866647 is an apocalyptic number.

801866647 is the 14159-th decagonal number.

801866647 is a deficient number, since it is larger than the sum of its proper divisors (70793).

801866647 is a wasteful number, since it uses less digits than its factorization.

801866647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70792.

The product of its (nonzero) digits is 387072, while the sum is 46.

The square root of 801866647 is about 28317.2499900679. The cubic root of 801866647 is about 929.0392232089.

The spelling of 801866647 in words is "eight hundred one million, eight hundred sixty-six thousand, six hundred forty-seven".