781379382421 has 64 divisors (see below), whose sum is σ = 919683072000. Its totient is φ = 656797715200.

The previous prime is 781379382401. The next prime is 781379382451. The reversal of 781379382421 is 124283973187.

It is not a de Polignac number, because 781379382421 - 2¹¹ = 781379380373 is a prime.

It is a super-2 number, since 2×781379382421² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781379382401) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 338404815 + ... + 338407123.

It is an arithmetic number, because the mean of its divisors is an integer number (14370048000).

Almost surely, 2^781379382421 is an apocalyptic number.

It is an amenable number.

781379382421 is a deficient number, since it is larger than the sum of its proper divisors (138303689579).

781379382421 is a wasteful number, since it uses less digits than its factorization.

781379382421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2730.

The product of its digits is 4064256, while the sum is 55.

The spelling of 781379382421 in words is "seven hundred eighty-one billion, three hundred seventy-nine million, three hundred eighty-two thousand, four hundred twenty-one".