7890121491840 has 1024 divisors, whose sum is σ = 32328499507200. Its totient is φ = 1781398241280.

The previous prime is 7890121491817. The next prime is 7890121491841. The reversal of 7890121491840 is 481941210987.

7890121491840 is a `hidden beast` number, since 7 + 8 + 90 + 1 + 21 + 491 + 8 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7890121491841) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 8384825770 + ... + 8384826710.

It is an arithmetic number, because the mean of its divisors is an integer number (31570800300).

Almost surely, 2^{7890121491840} is an apocalyptic number.

7890121491840 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7890121491840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16164249753600).

7890121491840 is an abundant number, since it is smaller than the sum of its proper divisors (24438378015360).

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

7890121491840 is a wasteful number, since it uses less digits than its factorization.

7890121491840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1752 (or 1734 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 54.

The spelling of 7890121491840 in words is "seven trillion, eight hundred ninety billion, one hundred twenty-one million, four hundred ninety-one thousand, eight hundred forty".