100218421 has 2 divisors, whose sum is σ = 100218422. Its totient is φ = 100218420.

The previous prime is 100218413. The next prime is 100218439. The reversal of 100218421 is 124812001.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56460196 + 43758225 = 7514^2 + 6615^2 .

It is a cyclic number.

It is not a de Polignac number, because 100218421 - 2³ = 100218413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100218401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50109210 + 50109211.

It is an arithmetic number, because the mean of its divisors is an integer number (50109211).

Almost surely, 2^100218421 is an apocalyptic number.

It is an amenable number.

100218421 is a deficient number, since it is larger than the sum of its proper divisors (1).

100218421 is an equidigital number, since it uses as much as digits as its factorization.

100218421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 100218421 is about 10010.9150930372. The cubic root of 100218421 is about 464.4965777735.

The spelling of 100218421 in words is "one hundred million, two hundred eighteen thousand, four hundred twenty-one".