21227678198 has 4 divisors (see below), whose sum is σ = 31841517300. Its totient is φ = 10613839098.

The previous prime is 21227678177. The next prime is 21227678231. The reversal of 21227678198 is 89187672212.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×21227678198² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5306919548 + ... + 5306919551.

It is an arithmetic number, because the mean of its divisors is an integer number (7960379325).

Almost surely, 2^21227678198 is an apocalyptic number.

21227678198 is a deficient number, since it is larger than the sum of its proper divisors (10613839102).

21227678198 is a wasteful number, since it uses less digits than its factorization.

21227678198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10613839101.

The product of its digits is 1354752, while the sum is 53.

The spelling of 21227678198 in words is "twenty-one billion, two hundred twenty-seven million, six hundred seventy-eight thousand, one hundred ninety-eight".