21849720105 has 16 divisors (see below), whose sum is σ = 35140694400. Its totient is φ = 11592803328.

The previous prime is 21849720089. The next prime is 21849720107. The reversal of 21849720105 is 50102794812.

It is not a de Polignac number, because 21849720105 - 2⁴ = 21849720089 is a prime.

It is a super-2 number, since 2×21849720105² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21849720107) 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, 3770805 + ... + 3776594.

It is an arithmetic number, because the mean of its divisors is an integer number (2196293400).

Almost surely, 2^21849720105 is an apocalyptic number.

It is an amenable number.

21849720105 is a deficient number, since it is larger than the sum of its proper divisors (13290974295).

21849720105 is a wasteful number, since it uses less digits than its factorization.

21849720105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7547600.

The product of its (nonzero) digits is 40320, while the sum is 39.

The spelling of 21849720105 in words is "twenty-one billion, eight hundred forty-nine million, seven hundred twenty thousand, one hundred five".