21661353004598 has 16 divisors (see below), whose sum is σ = 32961782615040. Its totient is φ = 10674204345000.

The previous prime is 21661353004553. The next prime is 21661353004619. The reversal of 21661353004598 is 89540035316612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27665528 + ... + 28437723.

It is an arithmetic number, because the mean of its divisors is an integer number (2060111413440).

Almost surely, 2^{21661353004598} is an apocalyptic number.

21661353004598 is a deficient number, since it is larger than the sum of its proper divisors (11300429610442).

21661353004598 is a wasteful number, since it uses less digits than its factorization.

21661353004598 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56106043.

The product of its (nonzero) digits is 4665600, while the sum is 53.

The spelling of 21661353004598 in words is "twenty-one trillion, six hundred sixty-one billion, three hundred fifty-three million, four thousand, five hundred ninety-eight".