21002050445 has 16 divisors (see below), whose sum is σ = 25891118208. Its totient is φ = 16342799040.

The previous prime is 21002050423. The next prime is 21002050471. The reversal of 21002050445 is 54405020012.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21002050445 is a prime.

It is a super-2 number, since 2×21002050445² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21002050445.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 709022 + ... + 738048.

It is an arithmetic number, because the mean of its divisors is an integer number (1618194888).

Almost surely, 2^21002050445 is an apocalyptic number.

It is an amenable number.

21002050445 is a deficient number, since it is larger than the sum of its proper divisors (4889067763).

21002050445 is a wasteful number, since it uses less digits than its factorization.

21002050445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32980.

The product of its (nonzero) digits is 1600, while the sum is 23.

Adding to 21002050445 its reverse (54405020012), we get a palindrome (75407070457).

The spelling of 21002050445 in words is "twenty-one billion, two million, fifty thousand, four hundred forty-five".