1611407801920 has 56 divisors (see below), whose sum is σ = 4385331238464. Its totient is φ = 552482674176.

The previous prime is 1611407801873. The next prime is 1611407801977. The reversal of 1611407801920 is 291087041161.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 359687002 + ... + 359691481.

Almost surely, 2^{1611407801920} is an apocalyptic number.

1611407801920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1611407801920 is an abundant number, since it is smaller than the sum of its proper divisors (2773923436544).

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

1611407801920 is an equidigital number, since it uses as much as digits as its factorization.

1611407801920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719378507 (or 719378497 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 40.

The spelling of 1611407801920 in words is "one trillion, six hundred eleven billion, four hundred seven million, eight hundred one thousand, nine hundred twenty".