61809533460 has 672 divisors, whose sum is σ = 218145312000. Its totient is φ = 14632814592.

The previous prime is 61809533459. The next prime is 61809533491. The reversal of 61809533460 is 6433590816.

61809533460 is a `hidden beast` number, since 6 + 180 + 9 + 5 + 3 + 3 + 460 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 567059886 + ... + 567059994.

It is an arithmetic number, because the mean of its divisors is an integer number (324621000).

Almost surely, 2^61809533460 is an apocalyptic number.

61809533460 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 61809533460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109072656000).

61809533460 is an abundant number, since it is smaller than the sum of its proper divisors (156335778540).

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

61809533460 is a wasteful number, since it uses less digits than its factorization.

61809533460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 61809533460 in words is "sixty-one billion, eight hundred nine million, five hundred thirty-three thousand, four hundred sixty".