21256016654356 has 12 divisors (see below), whose sum is σ = 40579668158400. Its totient is φ = 9661825751960.

The previous prime is 21256016654333. The next prime is 21256016654357. The reversal of 21256016654356 is 65345661065212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21256016654357) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241545643756 + ... + 241545643843.

It is an arithmetic number, because the mean of its divisors is an integer number (3381639013200).

Almost surely, 2^{21256016654356} is an apocalyptic number.

It is an amenable number.

21256016654356 is a deficient number, since it is larger than the sum of its proper divisors (19323651504044).

21256016654356 is a wasteful number, since it uses less digits than its factorization.

21256016654356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483091287614 (or 483091287612 counting only the distinct ones).

The product of its (nonzero) digits is 7776000, while the sum is 52.

The spelling of 21256016654356 in words is "twenty-one trillion, two hundred fifty-six billion, sixteen million, six hundred fifty-four thousand, three hundred fifty-six".