21661225466044 has 12 divisors (see below), whose sum is σ = 37974475199304. Its totient is φ = 10811375409104.

The previous prime is 21661225466003. The next prime is 21661225466057. The reversal of 21661225466044 is 44066452216612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4809328447 + ... + 4809332950.

It is an arithmetic number, because the mean of its divisors is an integer number (3164539599942).

Almost surely, 2^{21661225466044} is an apocalyptic number.

It is an amenable number.

21661225466044 is a deficient number, since it is larger than the sum of its proper divisors (16313249733260).

21661225466044 is a wasteful number, since it uses less digits than its factorization.

21661225466044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9618661964 (or 9618661962 counting only the distinct ones).

The product of its (nonzero) digits is 3317760, while the sum is 49.

The spelling of 21661225466044 in words is "twenty-one trillion, six hundred sixty-one billion, two hundred twenty-five million, four hundred sixty-six thousand, forty-four".