3694517821 has 4 divisors (see below), whose sum is σ = 3794369692. Its totient is φ = 3594665952.

The previous prime is 3694517789. The next prime is 3694517837. The reversal of 3694517821 is 1287154963.

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 1699912900 + 1994604921 = 41230^2 + 44661^2 .

It is a cyclic number.

It is not a de Polignac number, because 3694517821 - 2⁵ = 3694517789 is a prime.

It is a pancake number, because a pancake can be divided into 3694517821 parts by 85959 straight cuts.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3694517891) 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, 49925880 + ... + 49925953.

It is an arithmetic number, because the mean of its divisors is an integer number (948592423).

Almost surely, 2^3694517821 is an apocalyptic number.

It is an amenable number.

3694517821 is a deficient number, since it is larger than the sum of its proper divisors (99851871).

3694517821 is an equidigital number, since it uses as much as digits as its factorization.

3694517821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99851870.

The product of its digits is 362880, while the sum is 46.

The square root of 3694517821 is about 60782.5453646028. The cubic root of 3694517821 is about 1545.9161062138.

The spelling of 3694517821 in words is "three billion, six hundred ninety-four million, five hundred seventeen thousand, eight hundred twenty-one".