21151204464 has 80 divisors (see below), whose sum is σ = 59192218400. Its totient is φ = 6508030464.

The previous prime is 21151204463. The next prime is 21151204493. The reversal of 21151204464 is 46440215112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21151204463) 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, 5172 + ... + 205740.

It is an arithmetic number, because the mean of its divisors is an integer number (739902730).

Almost surely, 2^21151204464 is an apocalyptic number.

21151204464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21151204464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29596109200).

21151204464 is an abundant number, since it is smaller than the sum of its proper divisors (38041013936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21151204464 is a wasteful number, since it uses less digits than its factorization.

21151204464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200619 (or 200587 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

Adding to 21151204464 its reverse (46440215112), we get a palindrome (67591419576).

The spelling of 21151204464 in words is "twenty-one billion, one hundred fifty-one million, two hundred four thousand, four hundred sixty-four".