51402581 has 8 divisors (see below), whose sum is σ = 54209280. Its totient is φ = 48606048.

The previous prime is 51402563. The next prime is 51402607. The reversal of 51402581 is 18520415.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51402581 is a prime.

It is a super-2 number, since 2×51402581² = 5284450666923122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51402581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51402521) 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, 9305 + ... + 13761.

It is an arithmetic number, because the mean of its divisors is an integer number (6776160).

Almost surely, 2^51402581 is an apocalyptic number.

It is an amenable number.

51402581 is a deficient number, since it is larger than the sum of its proper divisors (2806699).

51402581 is a wasteful number, since it uses less digits than its factorization.

51402581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5083.

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 51402581 is about 7169.5593309491. The cubic root of 51402581 is about 371.8162005850.

Adding to 51402581 its reverse (18520415), we get a palindrome (69922996).

The spelling of 51402581 in words is "fifty-one million, four hundred two thousand, five hundred eighty-one".