51550401 has 24 divisors (see below), whose sum is σ = 84168480. Its totient is φ = 27905472.

The previous prime is 51550393. The next prime is 51550417. The reversal of 51550401 is 10405515.

It is not a de Polignac number, because 51550401 - 2³ = 51550393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (51550201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6436 + ... + 12021.

It is an arithmetic number, because the mean of its divisors is an integer number (3507020).

Almost surely, 2^51550401 is an apocalyptic number.

It is an amenable number.

51550401 is a deficient number, since it is larger than the sum of its proper divisors (32618079).

51550401 is a wasteful number, since it uses less digits than its factorization.

51550401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18493 (or 18486 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 51550401 is about 7179.8607925224. The cubic root of 51550401 is about 372.1722739476.

Adding to 51550401 its reverse (10405515), we get a palindrome (61955916).

The spelling of 51550401 in words is "fifty-one million, five hundred fifty thousand, four hundred one".