21289780454 has 4 divisors (see below), whose sum is σ = 31934670684. Its totient is φ = 10644890226.

The previous prime is 21289780453. The next prime is 21289780471. The reversal of 21289780454 is 45408798212.

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

It is a super-3 number, since 3×21289780454³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21289780453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5322445112 + ... + 5322445115.

It is an arithmetic number, because the mean of its divisors is an integer number (7983667671).

Almost surely, 2^21289780454 is an apocalyptic number.

21289780454 is a deficient number, since it is larger than the sum of its proper divisors (10644890230).

21289780454 is a wasteful number, since it uses less digits than its factorization.

21289780454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10644890229.

The product of its (nonzero) digits is 1290240, while the sum is 50.

The spelling of 21289780454 in words is "twenty-one billion, two hundred eighty-nine million, seven hundred eighty thousand, four hundred fifty-four".