221492723647 has 4 divisors (see below), whose sum is σ = 238530625480. Its totient is φ = 204454821816.

The previous prime is 221492723593. The next prime is 221492723657. The reversal of 221492723647 is 746327294122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221492723647 - 2¹¹ = 221492721599 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221492723647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221492723657) 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, 8518950897 + ... + 8518950922.

It is an arithmetic number, because the mean of its divisors is an integer number (59632656370).

Almost surely, 2^221492723647 is an apocalyptic number.

221492723647 is a deficient number, since it is larger than the sum of its proper divisors (17037901833).

221492723647 is a wasteful number, since it uses less digits than its factorization.

221492723647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17037901832.

The product of its digits is 2032128, while the sum is 49.

The spelling of 221492723647 in words is "two hundred twenty-one billion, four hundred ninety-two million, seven hundred twenty-three thousand, six hundred forty-seven".