10021921 has 12 divisors (see below), whose sum is σ = 12555732. Its totient is φ = 7928928.

The previous prime is 10021909. The next prime is 10021933. The reversal of 10021921 is 12912001.

It is an interprime number because it is at equal distance from previous prime (10021909) and next prime (10021933).

It can be written as a sum of positive squares in 2 ways, for example, as 1254400 + 8767521 = 1120^2 + 2961^2 .

It is not a de Polignac number, because 10021921 - 2²¹ = 7924769 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 10021895 and 10021904.

It is not an unprimeable number, because it can be changed into a prime (10027921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7230 + ... + 8503.

It is an arithmetic number, because the mean of its divisors is an integer number (1046311).

Almost surely, 2^10021921 is an apocalyptic number.

It is an amenable number.

10021921 is a deficient number, since it is larger than the sum of its proper divisors (2533811).

10021921 is a wasteful number, since it uses less digits than its factorization.

10021921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15760 (or 15753 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 10021921 is about 3165.7417772143. The cubic root of 10021921 is about 215.6007786558.

Adding to 10021921 its reverse (12912001), we get a palindrome (22933922).

The spelling of 10021921 in words is "ten million, twenty-one thousand, nine hundred twenty-one".