21206253711 has 16 divisors (see below), whose sum is σ = 28898784000. Its totient is φ = 13828022208.

The previous prime is 21206253707. The next prime is 21206253727. The reversal of 21206253711 is 11735260212.

It is not a de Polignac number, because 21206253711 - 2² = 21206253707 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21206253511) 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, 265806 + ... + 336251.

It is an arithmetic number, because the mean of its divisors is an integer number (1806174000).

Almost surely, 2^21206253711 is an apocalyptic number.

21206253711 is a deficient number, since it is larger than the sum of its proper divisors (7692530289).

21206253711 is a wasteful number, since it uses less digits than its factorization.

21206253711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602318.

The product of its (nonzero) digits is 5040, while the sum is 30.

The spelling of 21206253711 in words is "twenty-one billion, two hundred six million, two hundred fifty-three thousand, seven hundred eleven".