21249198686 has 16 divisors (see below), whose sum is σ = 32263736400. Its totient is φ = 10494667008.

The previous prime is 21249198667. The next prime is 21249198703. The reversal of 21249198686 is 68689194212.

It is a super-4 number, since 4×21249198686⁴ (a number of 42 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1421660 + ... + 1436528.

It is an arithmetic number, because the mean of its divisors is an integer number (2016483525).

Almost surely, 2^21249198686 is an apocalyptic number.

21249198686 is a deficient number, since it is larger than the sum of its proper divisors (11014537714).

21249198686 is a wasteful number, since it uses less digits than its factorization.

21249198686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23563.

The product of its digits is 2985984, while the sum is 56.

The spelling of 21249198686 in words is "twenty-one billion, two hundred forty-nine million, one hundred ninety-eight thousand, six hundred eighty-six".