21205167207 has 16 divisors (see below), whose sum is σ = 32344692480. Its totient is φ = 12105217152.

The previous prime is 21205167157. The next prime is 21205167257. The reversal of 21205167207 is 70276150212.

It is an interprime number because it is at equal distance from previous prime (21205167157) and next prime (21205167257).

It is not a de Polignac number, because 21205167207 - 2¹¹ = 21205165159 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21205167257) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 479193 + ... + 521570.

It is an arithmetic number, because the mean of its divisors is an integer number (2021543280).

Almost surely, 2^21205167207 is an apocalyptic number.

21205167207 is a deficient number, since it is larger than the sum of its proper divisors (11139525273).

21205167207 is a wasteful number, since it uses less digits than its factorization.

21205167207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1001782.

The product of its (nonzero) digits is 11760, while the sum is 33.

The spelling of 21205167207 in words is "twenty-one billion, two hundred five million, one hundred sixty-seven thousand, two hundred seven".