661369875276 has 288 divisors, whose sum is σ = 1818304443648. Its totient is φ = 185460088320.

The previous prime is 661369875227. The next prime is 661369875307. The reversal of 661369875276 is 672578963166.

It is a super-2 number, since 2×661369875276² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 775345266 + ... + 775346118.

It is an arithmetic number, because the mean of its divisors is an integer number (6313557096).

Almost surely, 2^661369875276 is an apocalyptic number.

661369875276 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661369875276, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (909152221824).

661369875276 is an abundant number, since it is smaller than the sum of its proper divisors (1156934568372).

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

661369875276 is a wasteful number, since it uses less digits than its factorization.

661369875276 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1269 (or 1248 counting only the distinct ones).

The product of its digits is 137168640, while the sum is 66.

The spelling of 661369875276 in words is "six hundred sixty-one billion, three hundred sixty-nine million, eight hundred seventy-five thousand, two hundred seventy-six".