699860021 has 4 divisors (see below), whose sum is σ = 799840032. Its totient is φ = 599880012.

The previous prime is 699860009. The next prime is 699860023. The reversal of 699860021 is 120068996.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 699860021 - 2²⁶ = 632751157 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 (699860023) 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, 49989995 + ... + 49990008.

It is an arithmetic number, because the mean of its divisors is an integer number (199960008).

Almost surely, 2^699860021 is an apocalyptic number.

It is an amenable number.

699860021 is a deficient number, since it is larger than the sum of its proper divisors (99980011).

699860021 is an equidigital number, since it uses as much as digits as its factorization.

699860021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99980010.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 699860021 is about 26454.8676239364. The cubic root of 699860021 is about 887.8448130760.

The spelling of 699860021 in words is "six hundred ninety-nine million, eight hundred sixty thousand, twenty-one".