21153143554 has 8 divisors (see below), whose sum is σ = 33596169228. Its totient is φ = 9954420480.

The previous prime is 21153143549. The next prime is 21153143567. The reversal of 21153143554 is 45534135112.

It can be written as a sum of positive squares in 2 ways, for example, as 19972190329 + 1180953225 = 141323^2 + 34365^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21153143554² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (34), and also a Moran number because the ratio is a prime number: 622151281 = 21153143554 / (2 + 1 + 1 + 5 + 3 + 1 + 4 + 3 + 5 + 5 + 4).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 311075607 + ... + 311075674.

Almost surely, 2^21153143554 is an apocalyptic number.

21153143554 is a deficient number, since it is larger than the sum of its proper divisors (12443025674).

21153143554 is a wasteful number, since it uses less digits than its factorization.

21153143554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 622151300.

The product of its digits is 36000, while the sum is 34.

Adding to 21153143554 its reverse (45534135112), we get a palindrome (66687278666).

The spelling of 21153143554 in words is "twenty-one billion, one hundred fifty-three million, one hundred forty-three thousand, five hundred fifty-four".