51665290 has 12 divisors (see below), whose sum is σ = 93038454. Its totient is φ = 20657024.

The previous prime is 51665279. The next prime is 51665293. The reversal of 51665290 is 9256615.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 51652969 + 12321 = 7187^2 + 111^2 .

It is not an unprimeable number, because it can be changed into a prime (51665293) 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 5 ways as a sum of consecutive naturals, for example, 21594 + ... + 23866.

Almost surely, 2^51665290 is an apocalyptic number.

51665290 is a deficient number, since it is larger than the sum of its proper divisors (41373164).

51665290 is an frugal number, since it uses more digits than its factorization.

51665290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4553 (or 2280 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 34.

The square root of 51665290 is about 7187.8571215627. The cubic root of 51665290 is about 372.4485522688.

The spelling of 51665290 in words is "fifty-one million, six hundred sixty-five thousand, two hundred ninety".