21000101197 has 2 divisors, whose sum is σ = 21000101198. Its totient is φ = 21000101196.

The previous prime is 21000101153. The next prime is 21000101237. The reversal of 21000101197 is 79110100012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14207209636 + 6792891561 = 119194^2 + 82419^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000101197 - 2⁷ = 21000101069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000101107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500050598 + 10500050599.

It is an arithmetic number, because the mean of its divisors is an integer number (10500050599).

Almost surely, 2^21000101197 is an apocalyptic number.

It is an amenable number.

21000101197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000101197 is an equidigital number, since it uses as much as digits as its factorization.

21000101197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126, while the sum is 22.

The spelling of 21000101197 in words is "twenty-one billion, one hundred one thousand, one hundred ninety-seven".