1663645419220 has 24 divisors (see below), whose sum is σ = 3493733791464. Its totient is φ = 665443232256.

The previous prime is 1663645419217. The next prime is 1663645419223. The reversal of 1663645419220 is 229145463661.

It is an interprime number because it is at equal distance from previous prime (1663645419217) and next prime (1663645419223).

It can be written as a sum of positive squares in 4 ways, for example, as 784705418896 + 878940000324 = 885836^2 + 937518^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663645419223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2832 + ... + 1824088.

It is an arithmetic number, because the mean of its divisors is an integer number (145572241311).

Almost surely, 2^{1663645419220} is an apocalyptic number.

1663645419220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1663645419220 is an abundant number, since it is smaller than the sum of its proper divisors (1830088372244).

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

1663645419220 is a wasteful number, since it uses less digits than its factorization.

1663645419220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1866939 (or 1866937 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 49.

The spelling of 1663645419220 in words is "one trillion, six hundred sixty-three billion, six hundred forty-five million, four hundred nineteen thousand, two hundred twenty".