51165987601 has 3 divisors (see below), whose sum is σ = 51166213801. Its totient is φ = 51165761402.

The previous prime is 51165987581. The next prime is 51165987767. The reversal of 51165987601 is 10678956115.

It is a happy number.

The square root of 51165987601 is 226199.

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

51165987601 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 51165987601 - 2¹³ = 51165979409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51165937601) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 113100 + ... + 339298.

Almost surely, 2^51165987601 is an apocalyptic number.

51165987601 is the 226199-th square number.

51165987601 is the 113100-th centered octagonal number.

It is an amenable number.

51165987601 is a deficient number, since it is larger than the sum of its proper divisors (226200).

51165987601 is an frugal number, since it uses more digits than its factorization.

51165987601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452398 (or 226199 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 49.

Multiplying 51165987601 by its sum of digits (49), we get a square (2507133392449 = 1583393²).

The spelling of 51165987601 in words is "fifty-one billion, one hundred sixty-five million, nine hundred eighty-seven thousand, six hundred one".