661523433120 has 144 divisors (see below), whose sum is σ = 2462671384992. Its totient is φ = 160369313280.

The previous prime is 661523433119. The next prime is 661523433149. The reversal of 661523433120 is 21334325166.

661523433120 is a `hidden beast` number, since 6 + 6 + 1 + 523 + 4 + 3 + 3 + 120 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×661523433120² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20865582 + ... + 20897261.

It is an arithmetic number, because the mean of its divisors is an integer number (17101884618).

Almost surely, 2^661523433120 is an apocalyptic number.

661523433120 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

661523433120 is an abundant number, since it is smaller than the sum of its proper divisors (1801147951872).

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

661523433120 is a wasteful number, since it uses less digits than its factorization.

661523433120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41762875 (or 41762864 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 36.

Adding to 661523433120 its reverse (21334325166), we get a palindrome (682857758286).

The spelling of 661523433120 in words is "six hundred sixty-one billion, five hundred twenty-three million, four hundred thirty-three thousand, one hundred twenty".