100491421 has 2 divisors, whose sum is σ = 100491422. Its totient is φ = 100491420.

The previous prime is 100491389. The next prime is 100491427. The reversal of 100491421 is 124194001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88623396 + 11868025 = 9414^2 + 3445^2 .

It is a cyclic number.

It is not a de Polignac number, because 100491421 - 2⁵ = 100491389 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 100491392 and 100491401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100491427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50245710 + 50245711.

It is an arithmetic number, because the mean of its divisors is an integer number (50245711).

Almost surely, 2^100491421 is an apocalyptic number.

It is an amenable number.

100491421 is a deficient number, since it is larger than the sum of its proper divisors (1).

100491421 is an equidigital number, since it uses as much as digits as its factorization.

100491421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 100491421 is about 10024.5409371203. The cubic root of 100491421 is about 464.9179660274.

The spelling of 100491421 in words is "one hundred million, four hundred ninety-one thousand, four hundred twenty-one".