100432781 has 2 divisors, whose sum is σ = 100432782. Its totient is φ = 100432780.

The previous prime is 100432757. The next prime is 100432793. The reversal of 100432781 is 187234001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 86676100 + 13756681 = 9310^2 + 3709^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100432781 is a prime.

It is a super-2 number, since 2×100432781² = 20173486998787922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 100432781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100432711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50216390 + 50216391.

It is an arithmetic number, because the mean of its divisors is an integer number (50216391).

Almost surely, 2^100432781 is an apocalyptic number.

It is an amenable number.

100432781 is a deficient number, since it is larger than the sum of its proper divisors (1).

100432781 is an equidigital number, since it uses as much as digits as its factorization.

100432781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 100432781 is about 10021.6156881014. The cubic root of 100432781 is about 464.8275168664.

Adding to 100432781 its reverse (187234001), we get a palindrome (287666782).

The spelling of 100432781 in words is "one hundred million, four hundred thirty-two thousand, seven hundred eighty-one".