51690449 has 4 divisors (see below), whose sum is σ = 51950400. Its totient is φ = 51430500.

The previous prime is 51690439. The next prime is 51690451. The reversal of 51690449 is 94409615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51690449 - 2¹⁶ = 51624913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51690439) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129677 + ... + 130074.

It is an arithmetic number, because the mean of its divisors is an integer number (12987600).

Almost surely, 2^51690449 is an apocalyptic number.

It is an amenable number.

51690449 is a deficient number, since it is larger than the sum of its proper divisors (259951).

51690449 is a wasteful number, since it uses less digits than its factorization.

51690449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259950.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 51690449 is about 7189.6070129041. The cubic root of 51690449 is about 372.5089984764.

The spelling of 51690449 in words is "fifty-one million, six hundred ninety thousand, four hundred forty-nine".