21384615550 has 24 divisors (see below), whose sum is σ = 39788078400. Its totient is φ = 8551116480.

The previous prime is 21384615541. The next prime is 21384615601. The reversal of 21384615550 is 5551648312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 93811 + ... + 227089.

It is an arithmetic number, because the mean of its divisors is an integer number (1657836600).

Almost surely, 2^21384615550 is an apocalyptic number.

21384615550 is a deficient number, since it is larger than the sum of its proper divisors (18403462850).

21384615550 is a wasteful number, since it uses less digits than its factorization.

21384615550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136500 (or 136495 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 40.

The spelling of 21384615550 in words is "twenty-one billion, three hundred eighty-four million, six hundred fifteen thousand, five hundred fifty".