210021953899 has 4 divisors (see below), whose sum is σ = 210033729136. Its totient is φ = 210010178664.

The previous prime is 210021953873. The next prime is 210021953927. The reversal of 210021953899 is 998359120012.

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

It is a cyclic number.

It is not a de Polignac number, because 210021953899 - 2⁹ = 210021953387 is a prime.

It is a super-2 number, since 2×210021953899² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (210021953849) 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, 5860824 + ... + 5896549.

It is an arithmetic number, because the mean of its divisors is an integer number (52508432284).

Almost surely, 2^210021953899 is an apocalyptic number.

210021953899 is a deficient number, since it is larger than the sum of its proper divisors (11775237).

210021953899 is a wasteful number, since it uses less digits than its factorization.

210021953899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11775236.

The product of its (nonzero) digits is 349920, while the sum is 49.

The spelling of 210021953899 in words is "two hundred ten billion, twenty-one million, nine hundred fifty-three thousand, eight hundred ninety-nine".