100400381 has 2 divisors, whose sum is σ = 100400382. Its totient is φ = 100400380.

The previous prime is 100400357. The next prime is 100400393. The reversal of 100400381 is 183004001.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74736025 + 25664356 = 8645^2 + 5066^2 .

It is a cyclic number.

It is not a de Polignac number, because 100400381 - 2¹⁰ = 100399357 is a prime.

It is a super-2 number, since 2×100400381² = 20160473009890322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100405381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50200190 + 50200191.

It is an arithmetic number, because the mean of its divisors is an integer number (50200191).

Almost surely, 2^100400381 is an apocalyptic number.

It is an amenable number.

100400381 is a deficient number, since it is larger than the sum of its proper divisors (1).

100400381 is an equidigital number, since it uses as much as digits as its factorization.

100400381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 100400381 is about 10019.9990518962. Note that the first 3 decimals coincide. The cubic root of 100400381 is about 464.7775264442. Note that the first 3 decimals are identical.

Adding to 100400381 its reverse (183004001), we get a palindrome (283404382).

The spelling of 100400381 in words is "one hundred million, four hundred thousand, three hundred eighty-one".