51216801 has 16 divisors (see below), whose sum is σ = 72612288. Its totient is φ = 32000000.

The previous prime is 51216757. The next prime is 51216833. The reversal of 51216801 is 10861215.

It is a 3-Lehmer number, since φ(51216801) divides (51216801-1)³.

It is a cyclic number.

It is not a de Polignac number, because 51216801 - 2¹⁰ = 51215777 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (51216301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10801 + ... + 14801.

It is an arithmetic number, because the mean of its divisors is an integer number (4538268).

Almost surely, 2^51216801 is an apocalyptic number.

51216801 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

51216801 is a deficient number, since it is larger than the sum of its proper divisors (21395487).

51216801 is a wasteful number, since it uses less digits than its factorization.

51216801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4272.

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 51216801 is about 7156.5914372696. The cubic root of 51216801 is about 371.3677185669.

The spelling of 51216801 in words is "fifty-one million, two hundred sixteen thousand, eight hundred one".