51251340 has 48 divisors (see below), whose sum is σ = 164005632. Its totient is φ = 11714496.

The previous prime is 51251287. The next prime is 51251359. The reversal of 51251340 is 4315215.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60594 + ... + 61433.

It is an arithmetic number, because the mean of its divisors is an integer number (3416784).

Almost surely, 2^51251340 is an apocalyptic number.

It is an amenable number.

51251340 is an abundant number, since it is smaller than the sum of its proper divisors (112754292).

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

51251340 is a wasteful number, since it uses less digits than its factorization.

51251340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122046 (or 122044 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 51251340 is about 7159.0041206861. The cubic root of 51251340 is about 371.4511793790.

Adding to 51251340 its reverse (4315215), we get a palindrome (55566555).

The spelling of 51251340 in words is "fifty-one million, two hundred fifty-one thousand, three hundred forty".