21015345454 has 4 divisors (see below), whose sum is σ = 31523018184. Its totient is φ = 10507672726.

The previous prime is 21015345437. The next prime is 21015345467. The reversal of 21015345454 is 45454351012.

21015345454 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

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

It is a super-2 number, since 2×21015345454² (a number of 21 digits) contains 22 as substring.

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, 5253836362 + ... + 5253836365.

It is an arithmetic number, because the mean of its divisors is an integer number (7880754546).

Almost surely, 2^21015345454 is an apocalyptic number.

21015345454 is a deficient number, since it is larger than the sum of its proper divisors (10507672730).

21015345454 is a wasteful number, since it uses less digits than its factorization.

21015345454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10507672729.

The product of its (nonzero) digits is 48000, while the sum is 34.

Adding to 21015345454 its reverse (45454351012), we get a palindrome (66469696466).

The spelling of 21015345454 in words is "twenty-one billion, fifteen million, three hundred forty-five thousand, four hundred fifty-four".