51720370 has 16 divisors (see below), whose sum is σ = 100258200. Its totient is φ = 19096704.

The previous prime is 51720359. The next prime is 51720373. The reversal of 51720370 is 7302715.

It can be written as a sum of positive squares in 4 ways, for example, as 21613201 + 30107169 = 4649^2 + 5487^2 .

It is not an unprimeable number, because it can be changed into a prime (51720373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 198795 + ... + 199054.

Almost surely, 2^51720370 is an apocalyptic number.

51720370 is a deficient number, since it is larger than the sum of its proper divisors (48537830).

51720370 is a wasteful number, since it uses less digits than its factorization.

51720370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397869.

The product of its (nonzero) digits is 1470, while the sum is 25.

The square root of 51720370 is about 7191.6875627352. The cubic root of 51720370 is about 372.5808601843.

The spelling of 51720370 in words is "fifty-one million, seven hundred twenty thousand, three hundred seventy".