921787439139 has 48 divisors (see below), whose sum is σ = 1543738520064. Its totient is φ = 519148828800.

The previous prime is 921787439137. The next prime is 921787439143. The reversal of 921787439139 is 931934787129.

921787439139 is a `hidden beast` number, since 9 + 2 + 178 + 74 + 391 + 3 + 9 = 666.

It is not a de Polignac number, because 921787439139 - 2¹ = 921787439137 is a prime.

It is a super-2 number, since 2×921787439139² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (921787439137) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1032559 + ... + 1705799.

It is an arithmetic number, because the mean of its divisors is an integer number (32161219168).

Almost surely, 2^921787439139 is an apocalyptic number.

921787439139 is a deficient number, since it is larger than the sum of its proper divisors (621951080925).

921787439139 is a wasteful number, since it uses less digits than its factorization.

921787439139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 673568 (or 673565 counting only the distinct ones).

The product of its digits is 20575296, while the sum is 63.

The spelling of 921787439139 in words is "nine hundred twenty-one billion, seven hundred eighty-seven million, four hundred thirty-nine thousand, one hundred thirty-nine".