51720135 has 32 divisors (see below), whose sum is σ = 84715200. Its totient is φ = 26938368.

The previous prime is 51720113. The next prime is 51720139. The reversal of 51720135 is 53102715.

It is not a de Polignac number, because 51720135 - 2¹² = 51716039 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51720139) 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, 162997 + ... + 163313.

It is an arithmetic number, because the mean of its divisors is an integer number (2647350).

Almost surely, 2^51720135 is an apocalyptic number.

51720135 is a deficient number, since it is larger than the sum of its proper divisors (32995065).

51720135 is a wasteful number, since it uses less digits than its factorization.

51720135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547.

The product of its (nonzero) digits is 1050, while the sum is 24.

The square root of 51720135 is about 7191.6712244095. The cubic root of 51720135 is about 372.5802958893.

The spelling of 51720135 in words is "fifty-one million, seven hundred twenty thousand, one hundred thirty-five".