21221800601 has 2 divisors, whose sum is σ = 21221800602. Its totient is φ = 21221800600.

The previous prime is 21221800559. The next prime is 21221800627. The reversal of 21221800601 is 10600812212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19415635600 + 1806165001 = 139340^2 + 42499^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221800601 - 2²⁶ = 21154691737 is a prime.

It is a super-2 number, since 2×21221800601² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21221800681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610900300 + 10610900301.

It is an arithmetic number, because the mean of its divisors is an integer number (10610900301).

Almost surely, 2^21221800601 is an apocalyptic number.

It is an amenable number.

21221800601 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221800601 is an equidigital number, since it uses as much as digits as its factorization.

21221800601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 23.

The spelling of 21221800601 in words is "twenty-one billion, two hundred twenty-one million, eight hundred thousand, six hundred one".