21255140354 has 16 divisors (see below), whose sum is σ = 36950587776. Its totient is φ = 8981044800.

The previous prime is 21255140293. The next prime is 21255140503. The reversal of 21255140354 is 45304155212.

It is a self number, because there is not a number n which added to its sum of digits gives 21255140354.

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 7 ways as a sum of consecutive naturals, for example, 10690727 + ... + 10692714.

It is an arithmetic number, because the mean of its divisors is an integer number (2309411736).

Almost surely, 2^21255140354 is an apocalyptic number.

21255140354 is a deficient number, since it is larger than the sum of its proper divisors (15695447422).

21255140354 is a wasteful number, since it uses less digits than its factorization.

21255140354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21383521.

The product of its (nonzero) digits is 24000, while the sum is 32.

Adding to 21255140354 its reverse (45304155212), we get a palindrome (66559295566).

The spelling of 21255140354 in words is "twenty-one billion, two hundred fifty-five million, one hundred forty thousand, three hundred fifty-four".