51690940 has 48 divisors (see below), whose sum is σ = 124637184. Its totient is φ = 17640000.

The previous prime is 51690937. The next prime is 51690941. The reversal of 51690940 is 4909615.

It is a junction number, because it is equal to n+sod(n) for n = 51690896 and 51690905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51690941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34405 + ... + 35875.

It is an arithmetic number, because the mean of its divisors is an integer number (2596608).

Almost surely, 2^51690940 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51690940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62318592).

51690940 is an abundant number, since it is smaller than the sum of its proper divisors (72946244).

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

51690940 is a wasteful number, since it uses less digits than its factorization.

51690940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1738 (or 1736 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 51690940 is about 7189.6411593347. The cubic root of 51690940 is about 372.5101779421.

The spelling of 51690940 in words is "fifty-one million, six hundred ninety thousand, nine hundred forty".