61066321920 has 168 divisors, whose sum is σ = 211684939596. Its totient is φ = 16284254208.

The previous prime is 61066321871. The next prime is 61066321957. The reversal of 61066321920 is 2912366016.

It is a happy number.

61066321920 is a `hidden beast` number, since 6 + 1 + 0 + 6 + 632 + 19 + 2 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 55138553856 + 5927768064 = 234816^2 + 76992^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 285814 + ... + 451466.

Almost surely, 2^61066321920 is an apocalyptic number.

61066321920 is a gapful number since it is divisible by the number (60) 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 61066321920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105842469798).

61066321920 is an abundant number, since it is smaller than the sum of its proper divisors (150618617676).

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

61066321920 is a wasteful number, since it uses less digits than its factorization.

61066321920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165690 (or 165663 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

Adding to 61066321920 its reverse (2912366016), we get a palindrome (63978687936).

The spelling of 61066321920 in words is "sixty-one billion, sixty-six million, three hundred twenty-one thousand, nine hundred twenty".