1921267547640 has 160 divisors (see below), whose sum is σ = 7380107174880. Its totient is φ = 439146862848.

The previous prime is 1921267547629. The next prime is 1921267547677. The reversal of 1921267547640 is 467457621291.

1921267547640 is a `hidden beast` number, since 1 + 9 + 2 + 126 + 7 + 5 + 476 + 40 = 666.

It is a super-2 number, since 2×1921267547640² (a number of 25 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 42333307 + ... + 42378666.

It is an arithmetic number, because the mean of its divisors is an integer number (46125669843).

Almost surely, 2^{1921267547640} is an apocalyptic number.

1921267547640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1921267547640 is an abundant number, since it is smaller than the sum of its proper divisors (5458839627240).

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

1921267547640 is a wasteful number, since it uses less digits than its factorization.

1921267547640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84712003 (or 84711990 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 54.

The spelling of 1921267547640 in words is "one trillion, nine hundred twenty-one billion, two hundred sixty-seven million, five hundred forty-seven thousand, six hundred forty".