221601654925 has 24 divisors (see below), whose sum is σ = 314061503936. Its totient is φ = 151945597440.

The previous prime is 221601654893. The next prime is 221601654947. The reversal of 221601654925 is 529456106122.

It is not a de Polignac number, because 221601654925 - 2⁵ = 221601654893 is a prime.

It is a Duffinian number.

It is a congruent 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, 3593149 + ... + 3654301.

Almost surely, 2^221601654925 is an apocalyptic number.

221601654925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221601654925 is a deficient number, since it is larger than the sum of its proper divisors (92459849011).

221601654925 is a wasteful number, since it uses less digits than its factorization.

221601654925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81877 (or 81872 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 43.

The spelling of 221601654925 in words is "two hundred twenty-one billion, six hundred one million, six hundred fifty-four thousand, nine hundred twenty-five".