21002066625 has 64 divisors (see below), whose sum is σ = 35344048896. Its totient is φ = 11074752000.

The previous prime is 21002066623. The next prime is 21002066663. The reversal of 21002066625 is 52666020012.

It is not a de Polignac number, because 21002066625 - 2¹ = 21002066623 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21002066592 and 21002066601.

It is not an unprimeable number, because it can be changed into a prime (21002066623) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13717110 + ... + 13718640.

It is an arithmetic number, because the mean of its divisors is an integer number (552250764).

Almost surely, 2^21002066625 is an apocalyptic number.

21002066625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21002066625 is a deficient number, since it is larger than the sum of its proper divisors (14341982271).

21002066625 is a wasteful number, since it uses less digits than its factorization.

21002066625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1939 (or 1929 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

Adding to 21002066625 its reverse (52666020012), we get a palindrome (73668086637).

The spelling of 21002066625 in words is "twenty-one billion, two million, sixty-six thousand, six hundred twenty-five".