61961166400 has 315 divisors, whose sum is σ = 179274669009. Its totient is φ = 21076554240.

The previous prime is 61961166353. The next prime is 61961166479. The reversal of 61961166400 is 466116916.

The square root of 61961166400 is 248920.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 22306019904 + 39655146496 = 149352^2 + 199136^2 .

It is a super-2 number, since 2×61961166400² (a number of 22 digits) contains 22 as substring.

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 (17) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 487883137 + ... + 487883263.

Almost surely, 2^61961166400 is an apocalyptic number.

61961166400 is the 248920-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61961166400

61961166400 is an abundant number, since it is smaller than the sum of its proper divisors (117313502609).

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

61961166400 is an frugal number, since it uses more digits than its factorization.

61961166400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 40.

The spelling of 61961166400 in words is "sixty-one billion, nine hundred sixty-one million, one hundred sixty-six thousand, four hundred".