61729668 has 192 divisors, whose sum is σ = 215255040. Its totient is φ = 14774400.

The previous prime is 61729667. The next prime is 61729693. The reversal of 61729668 is 86692716.

61729668 is a `hidden beast` number, since 617 + 29 + 6 + 6 + 8 = 666.

It is a super-2 number, since 2×61729668² = 7621103822780448, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61729663) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 107823 + ... + 108393.

It is an arithmetic number, because the mean of its divisors is an integer number (1121120).

Almost surely, 2^61729668 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61729668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107627520).

61729668 is an abundant number, since it is smaller than the sum of its proper divisors (153525372).

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

61729668 is a wasteful number, since it uses less digits than its factorization.

61729668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615 (or 607 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 61729668 is about 7856.8230220618. The cubic root of 61729668 is about 395.2130837703.

The spelling of 61729668 in words is "sixty-one million, seven hundred twenty-nine thousand, six hundred sixty-eight".