781131201221 has 8 divisors (see below), whose sum is σ = 892727143680. Its totient is φ = 669536701488.

The previous prime is 781131201211. The next prime is 781131201353. The reversal of 781131201221 is 122102131187.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 781131201221 - 2²⁶ = 781064092357 is a prime.

It is a super-2 number, since 2×781131201221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781131201211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1324340 + ... + 1821026.

It is an arithmetic number, because the mean of its divisors is an integer number (111590892960).

Almost surely, 2^781131201221 is an apocalyptic number.

It is an amenable number.

781131201221 is a deficient number, since it is larger than the sum of its proper divisors (111595942459).

781131201221 is a wasteful number, since it uses less digits than its factorization.

781131201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721363.

The product of its (nonzero) digits is 1344, while the sum is 29.

The spelling of 781131201221 in words is "seven hundred eighty-one billion, one hundred thirty-one million, two hundred one thousand, two hundred twenty-one".