21021020198 has 8 divisors (see below), whose sum is σ = 31542423192. Its totient is φ = 10506879136.

The previous prime is 21021020161. The next prime is 21021020239. The reversal of 21021020198 is 89102012012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1808240 + ... + 1819827.

It is an arithmetic number, because the mean of its divisors is an integer number (3942802899).

Almost surely, 2^21021020198 is an apocalyptic number.

21021020198 is a deficient number, since it is larger than the sum of its proper divisors (10521402994).

21021020198 is a wasteful number, since it uses less digits than its factorization.

21021020198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3630966.

The product of its (nonzero) digits is 576, while the sum is 26.

The spelling of 21021020198 in words is "twenty-one billion, twenty-one million, twenty thousand, one hundred ninety-eight".