51401821 has 4 divisors (see below), whose sum is σ = 54107200. Its totient is φ = 48696444.

The previous prime is 51401807. The next prime is 51401839. The reversal of 51401821 is 12810415.

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 a de Polignac number, because none of the positive numbers 2^k-51401821 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51401792 and 51401801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51401881) 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 3 ways as a sum of consecutive naturals, for example, 1352661 + ... + 1352698.

It is an arithmetic number, because the mean of its divisors is an integer number (13526800).

Almost surely, 2^51401821 is an apocalyptic number.

It is an amenable number.

51401821 is a deficient number, since it is larger than the sum of its proper divisors (2705379).

51401821 is a wasteful number, since it uses less digits than its factorization.

51401821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2705378.

The product of its (nonzero) digits is 320, while the sum is 22.

The square root of 51401821 is about 7169.5063288904. The cubic root of 51401821 is about 371.8143681108.

The spelling of 51401821 in words is "fifty-one million, four hundred one thousand, eight hundred twenty-one".