21080701644 has 24 divisors (see below), whose sum is σ = 49238677488. Its totient is φ = 7019704320.

The previous prime is 21080701639. The next prime is 21080701651. The reversal of 21080701644 is 44610708012.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 887317 + ... + 910764.

It is an arithmetic number, because the mean of its divisors is an integer number (2051611562).

Almost surely, 2^21080701644 is an apocalyptic number.

It is an amenable number.

21080701644 is an abundant number, since it is smaller than the sum of its proper divisors (28157975844).

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

21080701644 is a wasteful number, since it uses less digits than its factorization.

21080701644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1799065 (or 1799063 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 33.

The spelling of 21080701644 in words is "twenty-one billion, eighty million, seven hundred one thousand, six hundred forty-four".