21940101 has 12 divisors (see below), whose sum is σ = 31905900. Its totient is φ = 14527680.

The previous prime is 21940099. The next prime is 21940103. The reversal of 21940101 is 10104912.

It is an interprime number because it is at equal distance from previous prime (21940099) and next prime (21940103).

It can be written as a sum of positive squares in 2 ways, for example, as 5171076 + 16769025 = 2274^2 + 4095^2 .

It is not a de Polignac number, because 21940101 - 2¹ = 21940099 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21940103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6840 + ... + 9521.

It is an arithmetic number, because the mean of its divisors is an integer number (2658825).

Almost surely, 2^21940101 is an apocalyptic number.

It is an amenable number.

21940101 is a deficient number, since it is larger than the sum of its proper divisors (9965799).

21940101 is a wasteful number, since it uses less digits than its factorization.

21940101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16516 (or 16513 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 21940101 is about 4684.0261527878. The cubic root of 21940101 is about 279.9493998700.

The spelling of 21940101 in words is "twenty-one million, nine hundred forty thousand, one hundred one".