20210021099 has 4 divisors (see below), whose sum is σ = 21273706440. Its totient is φ = 19146335760.

The previous prime is 20210021059. The next prime is 20210021131. The reversal of 20210021099 is 99012001202.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20210021099 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20210021059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 531842642 + ... + 531842679.

It is an arithmetic number, because the mean of its divisors is an integer number (5318426610).

Almost surely, 2^20210021099 is an apocalyptic number.

20210021099 is a deficient number, since it is larger than the sum of its proper divisors (1063685341).

20210021099 is a wasteful number, since it uses less digits than its factorization.

20210021099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063685340.

The product of its (nonzero) digits is 648, while the sum is 26.

The spelling of 20210021099 in words is "twenty billion, two hundred ten million, twenty-one thousand, ninety-nine".