921787439140 has 24 divisors (see below), whose sum is σ = 1944206704440. Its totient is φ = 367104864768.

The previous prime is 921787439137. The next prime is 921787439143. The reversal of 921787439140 is 41934787129.

It is an interprime number because it is at equal distance from previous prime (921787439137) and next prime (921787439143).

It can be written as a sum of positive squares in 4 ways, for example, as 492534468864 + 429252970276 = 701808^2 + 655174^2 .

It is not an unprimeable number, because it can be changed into a prime (921787439143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100627237 + ... + 100636396.

It is an arithmetic number, because the mean of its divisors is an integer number (81008612685).

Almost surely, 2^921787439140 is an apocalyptic number.

It is an amenable number.

921787439140 is an abundant number, since it is smaller than the sum of its proper divisors (1022419265300).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

921787439140 is a wasteful number, since it uses less digits than its factorization.

921787439140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201263871 (or 201263869 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 55.

The spelling of 921787439140 in words is "nine hundred twenty-one billion, seven hundred eighty-seven million, four hundred thirty-nine thousand, one hundred forty".