51661608 has 64 divisors (see below), whose sum is σ = 136776000. Its totient is φ = 16215552.

The previous prime is 51661537. The next prime is 51661609. The reversal of 51661608 is 80616615.

It is a super-2 number, since 2×51661608² = 5337843482291328, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51661609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126108 + ... + 126516.

It is an arithmetic number, because the mean of its divisors is an integer number (2137125).

Almost surely, 2^51661608 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 51661608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68388000).

51661608 is an abundant number, since it is smaller than the sum of its proper divisors (85114392).

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

51661608 is a wasteful number, since it uses less digits than its factorization.

51661608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714 (or 710 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 51661608 is about 7187.6009905948. The cubic root of 51661608 is about 372.4397043676.

The spelling of 51661608 in words is "fifty-one million, six hundred sixty-one thousand, six hundred eight".