51399405 has 48 divisors (see below), whose sum is σ = 92416896. Its totient is φ = 26409600.

The previous prime is 51399377. The next prime is 51399409. The reversal of 51399405 is 50499315.

It is not a de Polignac number, because 51399405 - 2¹⁶ = 51333869 is a prime.

It is a super-3 number, since 3×51399405³ (a number of 24 digits) contains 333 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 51399405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51399409) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 195304 + ... + 195566.

It is an arithmetic number, because the mean of its divisors is an integer number (1925352).

Almost surely, 2^51399405 is an apocalyptic number.

It is an amenable number.

51399405 is a deficient number, since it is larger than the sum of its proper divisors (41017491).

51399405 is a wasteful number, since it uses less digits than its factorization.

51399405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418 (or 415 counting only the distinct ones).

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

The square root of 51399405 is about 7169.3378355327. The cubic root of 51399405 is about 371.8085426519.

The spelling of 51399405 in words is "fifty-one million, three hundred ninety-nine thousand, four hundred five".