51497820 has 144 divisors (see below), whose sum is σ = 176117760. Its totient is φ = 12067200.

The previous prime is 51497819. The next prime is 51497833. The reversal of 51497820 is 2879415.

51497820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 60961 + ... + 61799.

It is an arithmetic number, because the mean of its divisors is an integer number (1223040).

Almost surely, 2^51497820 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 51497820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88058880).

51497820 is an abundant number, since it is smaller than the sum of its proper divisors (124619940).

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

51497820 is a wasteful number, since it uses less digits than its factorization.

51497820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 896 (or 891 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 51497820 is about 7176.1981577992. The cubic root of 51497820 is about 372.0456933119.

The spelling of 51497820 in words is "fifty-one million, four hundred ninety-seven thousand, eight hundred twenty".