21510516404 has 24 divisors (see below), whose sum is σ = 40543291488. Its totient is φ = 9926892000.

The previous prime is 21510516373. The next prime is 21510516413. The reversal of 21510516404 is 40461501512.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 726539 + ... + 755565.

It is an arithmetic number, because the mean of its divisors is an integer number (1689303812).

Almost surely, 2^21510516404 is an apocalyptic number.

It is an amenable number.

21510516404 is a deficient number, since it is larger than the sum of its proper divisors (19032775084).

21510516404 is a wasteful number, since it uses less digits than its factorization.

21510516404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43295 (or 43293 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 29.

The spelling of 21510516404 in words is "twenty-one billion, five hundred ten million, five hundred sixteen thousand, four hundred four".