21040023454 has 16 divisors (see below), whose sum is σ = 32585366016. Its totient is φ = 10178386200.

The previous prime is 21040023449. The next prime is 21040023517. The reversal of 21040023454 is 45432004012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 261349 + ... + 332239.

It is an arithmetic number, because the mean of its divisors is an integer number (2036585376).

Almost surely, 2^21040023454 is an apocalyptic number.

21040023454 is a deficient number, since it is larger than the sum of its proper divisors (11545342562).

21040023454 is a wasteful number, since it uses less digits than its factorization.

21040023454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75711.

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 21040023454 its reverse (45432004012), we get a palindrome (66472027466).

The spelling of 21040023454 in words is "twenty-one billion, forty million, twenty-three thousand, four hundred fifty-four".