21010262609 has 8 divisors (see below), whose sum is σ = 24020924928. Its totient is φ = 18001899360.

The previous prime is 21010262599. The next prime is 21010262659. The reversal of 21010262609 is 90626201012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21010262609 - 2²⁴ = 20993485393 is a prime.

It is a super-2 number, since 2×21010262609² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21010262659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 555137 + ... + 591774.

It is an arithmetic number, because the mean of its divisors is an integer number (3002615616).

Almost surely, 2^21010262609 is an apocalyptic number.

It is an amenable number.

21010262609 is a deficient number, since it is larger than the sum of its proper divisors (3010662319).

21010262609 is a wasteful number, since it uses less digits than its factorization.

21010262609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1149535.

The product of its (nonzero) digits is 2592, while the sum is 29.

The spelling of 21010262609 in words is "twenty-one billion, ten million, two hundred sixty-two thousand, six hundred nine".