100137721 has 2 divisors, whose sum is σ = 100137722. Its totient is φ = 100137720.

The previous prime is 100137673. The next prime is 100137767. The reversal of 100137721 is 127731001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 97298496 + 2839225 = 9864^2 + 1685^2 .

It is a cyclic number.

It is not a de Polignac number, because 100137721 - 2⁷ = 100137593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 100137692 and 100137701.

It is not a weakly prime, because it can be changed into another prime (100137221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50068860 + 50068861.

It is an arithmetic number, because the mean of its divisors is an integer number (50068861).

Almost surely, 2^100137721 is an apocalyptic number.

It is an amenable number.

100137721 is a deficient number, since it is larger than the sum of its proper divisors (1).

100137721 is an equidigital number, since it uses as much as digits as its factorization.

100137721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 294, while the sum is 22.

The square root of 100137721 is about 10006.8836807470. The cubic root of 100137721 is about 464.3718670354.

Adding to 100137721 its reverse (127731001), we get a palindrome (227868722).

The spelling of 100137721 in words is "one hundred million, one hundred thirty-seven thousand, seven hundred twenty-one".