106921921 has 2 divisors, whose sum is σ = 106921922. Its totient is φ = 106921920.

The previous prime is 106921909. The next prime is 106921957. The reversal of 106921921 is 129129601.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 104775696 + 2146225 = 10236^2 + 1465^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-106921921 is a prime.

It is a super-2 number, since 2×106921921² = 22864594380660482, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (106921961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 53460960 + 53460961.

It is an arithmetic number, because the mean of its divisors is an integer number (53460961).

Almost surely, 2^106921921 is an apocalyptic number.

It is an amenable number.

106921921 is a deficient number, since it is larger than the sum of its proper divisors (1).

106921921 is an equidigital number, since it uses as much as digits as its factorization.

106921921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 106921921 is about 10340.3056531226. The cubic root of 106921921 is about 474.6304360887.

The spelling of 106921921 in words is "one hundred six million, nine hundred twenty-one thousand, nine hundred twenty-one".