51395661 has 16 divisors (see below), whose sum is σ = 76885120. Its totient is φ = 33929280.

The previous prime is 51395653. The next prime is 51395681. The reversal of 51395661 is 16659315.

It is not a de Polignac number, because 51395661 - 2³ = 51395653 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51395651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6460 + ... + 12021.

It is an arithmetic number, because the mean of its divisors is an integer number (4805320).

Almost surely, 2^51395661 is an apocalyptic number.

It is an amenable number.

51395661 is a deficient number, since it is larger than the sum of its proper divisors (25489459).

51395661 is a wasteful number, since it uses less digits than its factorization.

51395661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18593 (or 18587 counting only the distinct ones).

The product of its digits is 24300, while the sum is 36.

The square root of 51395661 is about 7169.0767187972. The cubic root of 51395661 is about 371.7995147589.

The spelling of 51395661 in words is "fifty-one million, three hundred ninety-five thousand, six hundred sixty-one".