21100601 has 2 divisors, whose sum is σ = 21100602. Its totient is φ = 21100600.

The previous prime is 21100579. The next prime is 21100613. The reversal of 21100601 is 10600112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11397376 + 9703225 = 3376^2 + 3115^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100601 - 2²² = 16906297 is a prime.

It is a super-2 number, since 2×21100601² = 890470725122402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21100631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550300 + 10550301.

It is an arithmetic number, because the mean of its divisors is an integer number (10550301).

Almost surely, 2^21100601 is an apocalyptic number.

It is an amenable number.

21100601 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100601 is an equidigital number, since it uses as much as digits as its factorization.

21100601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 21100601 is about 4593.5390495782. The cubic root of 21100601 is about 276.3322724043.

Adding to 21100601 its reverse (10600112), we get a palindrome (31700713).

The spelling of 21100601 in words is "twenty-one million, one hundred thousand, six hundred one".