21205154203 has 8 divisors (see below), whose sum is σ = 22227525936. Its totient is φ = 20206838400.

The previous prime is 21205154143. The next prime is 21205154209. The reversal of 21205154203 is 30245150212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21205154203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21205154209) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6012178 + ... + 6015703.

It is an arithmetic number, because the mean of its divisors is an integer number (2778440742).

Almost surely, 2^21205154203 is an apocalyptic number.

21205154203 is a deficient number, since it is larger than the sum of its proper divisors (1022371733).

21205154203 is a wasteful number, since it uses less digits than its factorization.

21205154203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12027965.

The product of its (nonzero) digits is 2400, while the sum is 25.

The spelling of 21205154203 in words is "twenty-one billion, two hundred five million, one hundred fifty-four thousand, two hundred three".