51620251 has 8 divisors (see below), whose sum is σ = 52760160. Its totient is φ = 50486592.

The previous prime is 51620243. The next prime is 51620269. The reversal of 51620251 is 15202615.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51620251 - 2³ = 51620243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51620651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17671 + ... + 20383.

It is an arithmetic number, because the mean of its divisors is an integer number (6595020).

Almost surely, 2^51620251 is an apocalyptic number.

51620251 is a deficient number, since it is larger than the sum of its proper divisors (1139909).

51620251 is a wasteful number, since it uses less digits than its factorization.

51620251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3125.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 51620251 is about 7184.7234463130. The cubic root of 51620251 is about 372.3402939834.

Adding to 51620251 its reverse (15202615), we get a palindrome (66822866).

The spelling of 51620251 in words is "fifty-one million, six hundred twenty thousand, two hundred fifty-one".