51406421 has 8 divisors (see below), whose sum is σ = 56282688. Its totient is φ = 46564000.

The previous prime is 51406417. The next prime is 51406429. The reversal of 51406421 is 12460415.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51406421 - 2² = 51406417 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51406429) 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 7 ways as a sum of consecutive naturals, for example, 5225 + ... + 11406.

It is an arithmetic number, because the mean of its divisors is an integer number (7035336).

Almost surely, 2^51406421 is an apocalyptic number.

It is an amenable number.

51406421 is a deficient number, since it is larger than the sum of its proper divisors (4876267).

51406421 is a wasteful number, since it uses less digits than its factorization.

51406421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16923.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 51406421 is about 7169.8271248336. The cubic root of 51406421 is about 371.8254591256.

Adding to 51406421 its reverse (12460415), we get a palindrome (63866836).

The spelling of 51406421 in words is "fifty-one million, four hundred six thousand, four hundred twenty-one".