21709475755 has 24 divisors (see below), whose sum is σ = 28793327472. Its totient is φ = 15701400000.

The previous prime is 21709475743. The next prime is 21709475783. The reversal of 21709475755 is 55757490712.

It is not a de Polignac number, because 21709475755 - 2¹⁵ = 21709442987 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10380 + ... + 208630.

It is an arithmetic number, because the mean of its divisors is an integer number (1199721978).

Almost surely, 2^21709475755 is an apocalyptic number.

21709475755 is a deficient number, since it is larger than the sum of its proper divisors (7083851717).

21709475755 is a wasteful number, since it uses less digits than its factorization.

21709475755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198459 (or 198448 counting only the distinct ones).

The product of its (nonzero) digits is 3087000, while the sum is 52.

The spelling of 21709475755 in words is "twenty-one billion, seven hundred nine million, four hundred seventy-five thousand, seven hundred fifty-five".