21346787197 has 8 divisors (see below), whose sum is σ = 21459395160. Its totient is φ = 21234450240.

The previous prime is 21346787153. The next prime is 21346787201. The reversal of 21346787197 is 79178764312.

It can be written as a sum of positive squares in 4 ways, for example, as 13213272601 + 8133514596 = 114949^2 + 90186^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21346787197 - 2¹⁹ = 21346262909 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 (21346787897) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91179 + ... + 225847.

It is an arithmetic number, because the mean of its divisors is an integer number (2682424395).

Almost surely, 2^21346787197 is an apocalyptic number.

It is an amenable number.

21346787197 is a deficient number, since it is larger than the sum of its proper divisors (112607963).

21346787197 is a wasteful number, since it uses less digits than its factorization.

21346787197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135503.

The product of its digits is 3556224, while the sum is 55.

The spelling of 21346787197 in words is "twenty-one billion, three hundred forty-six million, seven hundred eighty-seven thousand, one hundred ninety-seven".