51033661 has 4 divisors (see below), whose sum is σ = 58324192. Its totient is φ = 43743132.

The previous prime is 51033641. The next prime is 51033679. The reversal of 51033661 is 16633015.

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.

It is a cyclic number.

It is not a de Polignac number, because 51033661 - 2¹⁹ = 50509373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51033641) 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, 3645255 + ... + 3645268.

It is an arithmetic number, because the mean of its divisors is an integer number (14581048).

Almost surely, 2^51033661 is an apocalyptic number.

It is an amenable number.

51033661 is a deficient number, since it is larger than the sum of its proper divisors (7290531).

51033661 is an equidigital number, since it uses as much as digits as its factorization.

51033661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7290530.

The product of its (nonzero) digits is 1620, while the sum is 25.

The square root of 51033661 is about 7143.7847811927. The cubic root of 51033661 is about 370.9245468621.

Adding to 51033661 its reverse (16633015), we get a palindrome (67666676).

The spelling of 51033661 in words is "fifty-one million, thirty-three thousand, six hundred sixty-one".