4394207021 has 4 divisors (see below), whose sum is σ = 4501382844. Its totient is φ = 4287031200.

The previous prime is 4394206997. The next prime is 4394207089. The reversal of 4394207021 is 1207024934.

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 779191396 + 3615015625 = 27914^2 + 60125^2 .

It is a cyclic number.

It is not a de Polignac number, because 4394207021 - 2²⁶ = 4327098157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4394207221) 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, 53587850 + ... + 53587931.

It is an arithmetic number, because the mean of its divisors is an integer number (1125345711).

Almost surely, 2^4394207021 is an apocalyptic number.

4394207021 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

4394207021 is a deficient number, since it is larger than the sum of its proper divisors (107175823).

4394207021 is a wasteful number, since it uses less digits than its factorization.

4394207021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107175822.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 4394207021 is about 66288.8152028681. The cubic root of 4394207021 is about 1637.9230873505.

The spelling of 4394207021 in words is "four billion, three hundred ninety-four million, two hundred seven thousand, twenty-one".