21037001 has 4 divisors (see below), whose sum is σ = 21046272. Its totient is φ = 21027732.

The previous prime is 21036991. The next prime is 21037013. The reversal of 21037001 is 10073012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21037001 - 2⁶ = 21036937 is a prime.

It is a super-3 number, since 3×21037001³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21037021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1316 + ... + 6618.

It is an arithmetic number, because the mean of its divisors is an integer number (5261568).

Almost surely, 2^21037001 is an apocalyptic number.

It is an amenable number.

21037001 is a deficient number, since it is larger than the sum of its proper divisors (9271).

21037001 is an equidigital number, since it uses as much as digits as its factorization.

21037001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9270.

The product of its (nonzero) digits is 42, while the sum is 14.

The square root of 21037001 is about 4586.6110582869. The cubic root of 21037001 is about 276.0543589984.

The spelling of 21037001 in words is "twenty-one million, thirty-seven thousand, one".