21028437254 has 32 divisors (see below), whose sum is σ = 36558842400. Its totient is φ = 8979344640.

The previous prime is 21028437253. The next prime is 21028437259. The reversal of 21028437254 is 45273482012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21028437253) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 421799 + ... + 469010.

It is an arithmetic number, because the mean of its divisors is an integer number (1142463825).

Almost surely, 2^21028437254 is an apocalyptic number.

21028437254 is a deficient number, since it is larger than the sum of its proper divisors (15530405146).

21028437254 is a wasteful number, since it uses less digits than its factorization.

21028437254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 890888.

The product of its (nonzero) digits is 107520, while the sum is 38.

The spelling of 21028437254 in words is "twenty-one billion, twenty-eight million, four hundred thirty-seven thousand, two hundred fifty-four".