21002373 has 48 divisors (see below), whose sum is σ = 36481536. Its totient is φ = 11393280.

The previous prime is 21002357. The next prime is 21002389. The reversal of 21002373 is 37320012.

It is an interprime number because it is at equal distance from previous prime (21002357) and next prime (21002389).

It is not a de Polignac number, because 21002373 - 2⁴ = 21002357 is a prime.

It is a super-2 number, since 2×21002373² = 882199343262258, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002323) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 121315 + ... + 121487.

It is an arithmetic number, because the mean of its divisors is an integer number (760032).

Almost surely, 2^21002373 is an apocalyptic number.

It is an amenable number.

21002373 is a deficient number, since it is larger than the sum of its proper divisors (15479163).

21002373 is a wasteful number, since it uses less digits than its factorization.

21002373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274 (or 271 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 18.

The square root of 21002373 is about 4582.8346031687. The cubic root of 21002373 is about 275.9028091944.

Adding to 21002373 its reverse (37320012), we get a palindrome (58322385).

The spelling of 21002373 in words is "twenty-one million, two thousand, three hundred seventy-three".