21026624197 has 2 divisors, whose sum is σ = 21026624198. Its totient is φ = 21026624196.

The previous prime is 21026624183. The next prime is 21026624237. The reversal of 21026624197 is 79142662012.

It is an a-pointer prime, because the next prime (21026624237) can be obtained adding 21026624197 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13961549281 + 7065074916 = 118159^2 + 84054^2 .

It is a cyclic number.

It is not a de Polignac number, because 21026624197 - 2¹⁵ = 21026591429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21026624147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10513312098 + 10513312099.

It is an arithmetic number, because the mean of its divisors is an integer number (10513312099).

Almost surely, 2^21026624197 is an apocalyptic number.

It is an amenable number.

21026624197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21026624197 is an equidigital number, since it uses as much as digits as its factorization.

21026624197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 40.

The spelling of 21026624197 in words is "twenty-one billion, twenty-six million, six hundred twenty-four thousand, one hundred ninety-seven".