21438000185811 has 16 divisors (see below), whose sum is σ = 31183188872448. Its totient is φ = 12992459407200.

The previous prime is 21438000185743. The next prime is 21438000185923. The reversal of 21438000185811 is 11858100083412.

It is not a de Polignac number, because 21438000185811 - 2⁷ = 21438000185683 is a prime.

It is a super-3 number, since 3×21438000185811³ (a number of 41 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21438000185611) 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, 5069311 + ... + 8280936.

It is an arithmetic number, because the mean of its divisors is an integer number (1948949304528).

Almost surely, 2^{21438000185811} is an apocalyptic number.

21438000185811 is a deficient number, since it is larger than the sum of its proper divisors (9745188686637).

21438000185811 is a wasteful number, since it uses less digits than its factorization.

21438000185811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13398922.

The product of its (nonzero) digits is 61440, while the sum is 42.

The spelling of 21438000185811 in words is "twenty-one trillion, four hundred thirty-eight billion, one hundred eighty-five thousand, eight hundred eleven".