21106521454 has 4 divisors (see below), whose sum is σ = 31659782184. Its totient is φ = 10553260726.

The previous prime is 21106521433. The next prime is 21106521493. The reversal of 21106521454 is 45412560112.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5276630362 + ... + 5276630365.

It is an arithmetic number, because the mean of its divisors is an integer number (7914945546).

Almost surely, 2^21106521454 is an apocalyptic number.

21106521454 is a deficient number, since it is larger than the sum of its proper divisors (10553260730).

21106521454 is a wasteful number, since it uses less digits than its factorization.

21106521454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10553260729.

The product of its (nonzero) digits is 9600, while the sum is 31.

The spelling of 21106521454 in words is "twenty-one billion, one hundred six million, five hundred twenty-one thousand, four hundred fifty-four".