21702001 has 2 divisors, whose sum is σ = 21702002. Its totient is φ = 21702000.

The previous prime is 21701987. The next prime is 21702049. The reversal of 21702001 is 10020712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13727025 + 7974976 = 3705^2 + 2824^2 .

It is a cyclic number.

It is not a de Polignac number, because 21702001 - 2⁷ = 21701873 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21702301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10851000 + 10851001.

It is an arithmetic number, because the mean of its divisors is an integer number (10851001).

Almost surely, 2^21702001 is an apocalyptic number.

It is an amenable number.

21702001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21702001 is an equidigital number, since it uses as much as digits as its factorization.

21702001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 21702001 is about 4658.5406513199. The cubic root of 21702001 is about 278.9330183539.

Adding to 21702001 its reverse (10020712), we get a palindrome (31722713).

The spelling of 21702001 in words is "twenty-one million, seven hundred two thousand, one".