21200421045 has 32 divisors (see below), whose sum is σ = 34171632000. Its totient is φ = 11223344384.

The previous prime is 21200421041. The next prime is 21200421049. The reversal of 21200421045 is 54012400212.

It is an interprime number because it is at equal distance from previous prime (21200421041) and next prime (21200421049).

It is a cyclic number.

It is not a de Polignac number, because 21200421045 - 2² = 21200421041 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200421041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5010991 + ... + 5015219.

It is an arithmetic number, because the mean of its divisors is an integer number (1067863500).

Almost surely, 2^21200421045 is an apocalyptic number.

It is an amenable number.

21200421045 is a deficient number, since it is larger than the sum of its proper divisors (12971210955).

21200421045 is a wasteful number, since it uses less digits than its factorization.

21200421045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6629.

The product of its (nonzero) digits is 640, while the sum is 21.

Adding to 21200421045 its reverse (54012400212), we get a palindrome (75212821257).

The spelling of 21200421045 in words is "twenty-one billion, two hundred million, four hundred twenty-one thousand, forty-five".