21534204053 has 2 divisors, whose sum is σ = 21534204054. Its totient is φ = 21534204052.

The previous prime is 21534203993. The next prime is 21534204067. The reversal of 21534204053 is 35040243512.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13088961649 + 8445242404 = 114407^2 + 91898^2 .

It is a cyclic number.

It is not a de Polignac number, because 21534204053 - 2²⁸ = 21265768597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21534204253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10767102026 + 10767102027.

It is an arithmetic number, because the mean of its divisors is an integer number (10767102027).

Almost surely, 2^21534204053 is an apocalyptic number.

It is an amenable number.

21534204053 is a deficient number, since it is larger than the sum of its proper divisors (1).

21534204053 is an equidigital number, since it uses as much as digits as its factorization.

21534204053 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 29.

Adding to 21534204053 its reverse (35040243512), we get a palindrome (56574447565).

The spelling of 21534204053 in words is "twenty-one billion, five hundred thirty-four million, two hundred four thousand, fifty-three".