21454051252 has 6 divisors (see below), whose sum is σ = 37544589698. Its totient is φ = 10727025624.

The previous prime is 21454051243. The next prime is 21454051273. The reversal of 21454051252 is 25215045412.

It can be written as a sum of positive squares in only one way, i.e., 21247726756 + 206324496 = 145766^2 + 14364^2 .

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, 2681756403 + ... + 2681756410.

Almost surely, 2^21454051252 is an apocalyptic number.

It is an amenable number.

21454051252 is a deficient number, since it is larger than the sum of its proper divisors (16090538446).

21454051252 is a wasteful number, since it uses less digits than its factorization.

21454051252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5363512817 (or 5363512815 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 31.

Adding to 21454051252 its reverse (25215045412), we get a palindrome (46669096664).

The spelling of 21454051252 in words is "twenty-one billion, four hundred fifty-four million, fifty-one thousand, two hundred fifty-two".