101017921 has 2 divisors, whose sum is σ = 101017922. Its totient is φ = 101017920.

The previous prime is 101017919. The next prime is 101017949. The reversal of 101017921 is 129710101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78588225 + 22429696 = 8865^2 + 4736^2 .

It is a cyclic number.

It is not a de Polignac number, because 101017921 - 2¹ = 101017919 is a prime.

Together with 101017919, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 101017892 and 101017901.

It is not a weakly prime, because it can be changed into another prime (101017901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50508960 + 50508961.

It is an arithmetic number, because the mean of its divisors is an integer number (50508961).

Almost surely, 2^101017921 is an apocalyptic number.

It is an amenable number.

101017921 is a deficient number, since it is larger than the sum of its proper divisors (1).

101017921 is an equidigital number, since it uses as much as digits as its factorization.

101017921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126, while the sum is 22.

The square root of 101017921 is about 10050.7671846481. The cubic root of 101017921 is about 465.7284931341.

The spelling of 101017921 in words is "one hundred one million, seventeen thousand, nine hundred twenty-one".