51720290 has 32 divisors (see below), whose sum is σ = 98993664. Its totient is φ = 19388160.

The previous prime is 51720289. The next prime is 51720293. The reversal of 51720290 is 9202715.

It is not an unprimeable number, because it can be changed into a prime (51720293) 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, 51695 + ... + 52685.

It is an arithmetic number, because the mean of its divisors is an integer number (3093552).

Almost surely, 2^51720290 is an apocalyptic number.

51720290 is a deficient number, since it is larger than the sum of its proper divisors (47273374).

51720290 is a wasteful number, since it uses less digits than its factorization.

51720290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1322.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 51720290 is about 7191.6820007562. The cubic root of 51720290 is about 372.5806680841.

The spelling of 51720290 in words is "fifty-one million, seven hundred twenty thousand, two hundred ninety".