51620389 has 2 divisors, whose sum is σ = 51620390. Its totient is φ = 51620388.

The previous prime is 51620383. The next prime is 51620423. The reversal of 51620389 is 98302615.

It is an a-pointer prime, because the next prime (51620423) can be obtained adding 51620389 to its sum of digits (34).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49589764 + 2030625 = 7042^2 + 1425^2 .

It is a cyclic number.

It is not a de Polignac number, because 51620389 - 2²¹ = 49523237 is a prime.

It is a super-2 number, since 2×51620389² = 5329329121022642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51620383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25810194 + 25810195.

It is an arithmetic number, because the mean of its divisors is an integer number (25810195).

Almost surely, 2^51620389 is an apocalyptic number.

It is an amenable number.

51620389 is a deficient number, since it is larger than the sum of its proper divisors (1).

51620389 is an equidigital number, since it uses as much as digits as its factorization.

51620389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 51620389 is about 7184.7330500165. The cubic root of 51620389 is about 372.3406257842.

The spelling of 51620389 in words is "fifty-one million, six hundred twenty thousand, three hundred eighty-nine".