1921144653225 has 168 divisors, whose sum is σ = 4158969648192. Its totient is φ = 861664003200.

The previous prime is 1921144653173. The next prime is 1921144653227. The reversal of 1921144653225 is 5223564411291.

1921144653225 is a `hidden beast` number, since 1 + 92 + 1 + 1 + 4 + 4 + 6 + 532 + 25 = 666.

It is not a de Polignac number, because 1921144653225 - 2¹⁴ = 1921144636841 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1921144653227) by changing a digit.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 6619410 + ... + 6903540.

Almost surely, 2^{1921144653225} is an apocalyptic number.

1921144653225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1921144653225 is an abundant number, since it is smaller than the sum of its proper divisors (2237824994967).

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

1921144653225 is an equidigital number, since it uses as much as digits as its factorization.

1921144653225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284219 (or 284199 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The spelling of 1921144653225 in words is "one trillion, nine hundred twenty-one billion, one hundred forty-four million, six hundred fifty-three thousand, two hundred twenty-five".