21002121453 has 16 divisors (see below), whose sum is σ = 30136124736. Its totient is φ = 12961770240.

The previous prime is 21002121451. The next prime is 21002121457. The reversal of 21002121453 is 35412120012.

It is not a de Polignac number, because 21002121453 - 2¹ = 21002121451 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002121451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3372351 + ... + 3378572.

It is an arithmetic number, because the mean of its divisors is an integer number (1883507796).

Almost surely, 2^21002121453 is an apocalyptic number.

It is an amenable number.

21002121453 is a deficient number, since it is larger than the sum of its proper divisors (9134003283).

21002121453 is a wasteful number, since it uses less digits than its factorization.

21002121453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6751004.

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21002121453 its reverse (35412120012), we get a palindrome (56414241465).

The spelling of 21002121453 in words is "twenty-one billion, two million, one hundred twenty-one thousand, four hundred fifty-three".