21220101197 has 4 divisors (see below), whose sum is σ = 21387188736. Its totient is φ = 21053013660.

The previous prime is 21220101187. The next prime is 21220101209. The reversal of 21220101197 is 79110102212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21220101197 - 2²⁸ = 20951665741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220101137) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83543579 + ... + 83543832.

It is an arithmetic number, because the mean of its divisors is an integer number (5346797184).

Almost surely, 2^21220101197 is an apocalyptic number.

It is an amenable number.

21220101197 is a deficient number, since it is larger than the sum of its proper divisors (167087539).

21220101197 is a wasteful number, since it uses less digits than its factorization.

21220101197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167087538.

The product of its (nonzero) digits is 504, while the sum is 26.

The spelling of 21220101197 in words is "twenty-one billion, two hundred twenty million, one hundred one thousand, one hundred ninety-seven".