100021399 has 2 divisors, whose sum is σ = 100021400. Its totient is φ = 100021398.

The previous prime is 100021393. The next prime is 100021409. The reversal of 100021399 is 993120001.

It is a weak prime.

It is an emirp because it is prime and its reverse (993120001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 100021399 - 2⁵ = 100021367 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100021393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50010699 + 50010700.

It is an arithmetic number, because the mean of its divisors is an integer number (50010700).

Almost surely, 2^100021399 is an apocalyptic number.

100021399 is a deficient number, since it is larger than the sum of its proper divisors (1).

100021399 is an equidigital number, since it uses as much as digits as its factorization.

100021399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 100021399 is about 10001.0698927665. The cubic root of 100021399 is about 464.1919894531.

The spelling of 100021399 in words is "one hundred million, twenty-one thousand, three hundred ninety-nine".