51028561 has 4 divisors (see below), whose sum is σ = 51418224. Its totient is φ = 50638900.

The previous prime is 51028541. The next prime is 51028567. The reversal of 51028561 is 16582015.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16582015 = 5 ⋅3316403.

It is a cyclic number.

It is not a de Polignac number, because 51028561 - 2¹³ = 51020369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51028567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194635 + ... + 194896.

It is an arithmetic number, because the mean of its divisors is an integer number (12854556).

Almost surely, 2^51028561 is an apocalyptic number.

It is an amenable number.

51028561 is a deficient number, since it is larger than the sum of its proper divisors (389663).

51028561 is a wasteful number, since it uses less digits than its factorization.

51028561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389662.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 51028561 is about 7143.4278186316. The cubic root of 51028561 is about 370.9121904541.

The spelling of 51028561 in words is "fifty-one million, twenty-eight thousand, five hundred sixty-one".