21551147668 has 48 divisors (see below), whose sum is σ = 38933032320. Its totient is φ = 10431833600.

The previous prime is 21551147621. The next prime is 21551147671. The reversal of 21551147668 is 86674115512.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

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 15 ways as a sum of consecutive naturals, for example, 13717323 + ... + 13718893.

It is an arithmetic number, because the mean of its divisors is an integer number (811104840).

Almost surely, 2^21551147668 is an apocalyptic number.

It is an amenable number.

21551147668 is a deficient number, since it is larger than the sum of its proper divisors (17381884652).

21551147668 is a wasteful number, since it uses less digits than its factorization.

21551147668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2208 (or 2206 counting only the distinct ones).

The product of its digits is 403200, while the sum is 46.

The spelling of 21551147668 in words is "twenty-one billion, five hundred fifty-one million, one hundred forty-seven thousand, six hundred sixty-eight".