21865001607 has 12 divisors (see below), whose sum is σ = 31889410384. Its totient is φ = 14435146080.

The previous prime is 21865001597. The next prime is 21865001633. The reversal of 21865001607 is 70610056812.

It is not a de Polignac number, because 21865001607 - 2¹⁹ = 21864477319 is a prime.

It is a super-2 number, since 2×21865001607² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21865005607) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11792494 + ... + 11794347.

Almost surely, 2^21865001607 is an apocalyptic number.

21865001607 is a deficient number, since it is larger than the sum of its proper divisors (10024408777).

21865001607 is a wasteful number, since it uses less digits than its factorization.

21865001607 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23586950 (or 23586947 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 21865001607 in words is "twenty-one billion, eight hundred sixty-five million, one thousand, six hundred seven".