51653643 has 4 divisors (see below), whose sum is σ = 68871528. Its totient is φ = 34435760.

The previous prime is 51653629. The next prime is 51653663. The reversal of 51653643 is 34635615.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51653643 - 2⁶ = 51653579 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51653663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8608938 + ... + 8608943.

It is an arithmetic number, because the mean of its divisors is an integer number (17217882).

Almost surely, 2^51653643 is an apocalyptic number.

51653643 is a deficient number, since it is larger than the sum of its proper divisors (17217885).

51653643 is a wasteful number, since it uses less digits than its factorization.

51653643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17217884.

The product of its digits is 32400, while the sum is 33.

The square root of 51653643 is about 7187.0468900655. The cubic root of 51653643 is about 372.4205629147.

The spelling of 51653643 in words is "fifty-one million, six hundred fifty-three thousand, six hundred forty-three".