51801645 has 32 divisors (see below), whose sum is σ = 95090688. Its totient is φ = 23588928.

The previous prime is 51801641. The next prime is 51801647. The reversal of 51801645 is 54610815.

It is not a de Polignac number, because 51801645 - 2² = 51801641 is a prime.

It is a super-3 number, since 3×51801645³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51801641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31432 + ... + 33038.

It is an arithmetic number, because the mean of its divisors is an integer number (2971584).

Almost surely, 2^51801645 is an apocalyptic number.

It is an amenable number.

51801645 is a deficient number, since it is larger than the sum of its proper divisors (43289043).

51801645 is a wasteful number, since it uses less digits than its factorization.

51801645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1929.

The product of its (nonzero) digits is 4800, while the sum is 30.

The square root of 51801645 is about 7197.3359654806. The cubic root of 51801645 is about 372.7759197677.

The spelling of 51801645 in words is "fifty-one million, eight hundred one thousand, six hundred forty-five".