21019007 has 2 divisors, whose sum is σ = 21019008. Its totient is φ = 21019006.

The previous prime is 21019001. The next prime is 21019043. The reversal of 21019007 is 70091012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21019007 - 2¹⁴ = 21002623 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21019007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21019001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10509503 + 10509504.

It is an arithmetic number, because the mean of its divisors is an integer number (10509504).

Almost surely, 2^21019007 is an apocalyptic number.

21019007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21019007 is an equidigital number, since it uses as much as digits as its factorization.

21019007 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 21019007 is about 4584.6490596337. The cubic root of 21019007 is about 275.9756288429.

The spelling of 21019007 in words is "twenty-one million, nineteen thousand, seven".