51206140 has 24 divisors (see below), whose sum is σ = 113193360. Its totient is φ = 19404288.

The previous prime is 51206131. The next prime is 51206153. The reversal of 51206140 is 4160215.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66997 + ... + 67756.

It is an arithmetic number, because the mean of its divisors is an integer number (4716390).

Almost surely, 2^51206140 is an apocalyptic number.

It is an amenable number.

51206140 is an abundant number, since it is smaller than the sum of its proper divisors (61987220).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51206140 is a wasteful number, since it uses less digits than its factorization.

51206140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134781 (or 134779 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 51206140 is about 7155.8465606803. The cubic root of 51206140 is about 371.3419495100.

Adding to 51206140 its reverse (4160215), we get a palindrome (55366355).

The spelling of 51206140 in words is "fifty-one million, two hundred six thousand, one hundred forty".