101638109 has 2 divisors, whose sum is σ = 101638110. Its totient is φ = 101638108.

The previous prime is 101638093. The next prime is 101638151. The reversal of 101638109 is 901836101.

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., 54715609 + 46922500 = 7397^2 + 6850^2 .

It is a cyclic number.

It is not a de Polignac number, because 101638109 - 2⁴ = 101638093 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (101632109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50819054 + 50819055.

It is an arithmetic number, because the mean of its divisors is an integer number (50819055).

Almost surely, 2^101638109 is an apocalyptic number.

It is an amenable number.

101638109 is a deficient number, since it is larger than the sum of its proper divisors (1).

101638109 is an equidigital number, since it uses as much as digits as its factorization.

101638109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 101638109 is about 10081.5727443688. The cubic root of 101638109 is about 466.6796449338.

The spelling of 101638109 in words is "one hundred one million, six hundred thirty-eight thousand, one hundred nine".