21052454026 has 4 divisors (see below), whose sum is σ = 31578681042. Its totient is φ = 10526227012.

The previous prime is 21052454011. The next prime is 21052454029. The reversal of 21052454026 is 62045425012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18587232225 + 2465221801 = 136335^2 + 49651^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21052454029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5263113505 + ... + 5263113508.

Almost surely, 2^21052454026 is an apocalyptic number.

21052454026 is a deficient number, since it is larger than the sum of its proper divisors (10526227016).

21052454026 is a wasteful number, since it uses less digits than its factorization.

21052454026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10526227015.

The product of its (nonzero) digits is 19200, while the sum is 31.

Adding to 21052454026 its reverse (62045425012), we get a palindrome (83097879038).

The spelling of 21052454026 in words is "twenty-one billion, fifty-two million, four hundred fifty-four thousand, twenty-six".