51221885 has 32 divisors (see below), whose sum is σ = 73301760. Its totient is φ = 33868800.

The previous prime is 51221881. The next prime is 51221893. The reversal of 51221885 is 58812215.

It is a happy number.

It is not a de Polignac number, because 51221885 - 2² = 51221881 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51221881) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50261 + ... + 51269.

It is an arithmetic number, because the mean of its divisors is an integer number (2290680).

Almost surely, 2^51221885 is an apocalyptic number.

51221885 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

51221885 is a deficient number, since it is larger than the sum of its proper divisors (22079875).

51221885 is a wasteful number, since it uses less digits than its factorization.

51221885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1109.

The product of its digits is 6400, while the sum is 32.

The square root of 51221885 is about 7156.9466254821. The cubic root of 51221885 is about 371.3800060128.

It can be divided in two parts, 5122 and 1885, that added together give a palindrome (7007).

The spelling of 51221885 in words is "fifty-one million, two hundred twenty-one thousand, eight hundred eighty-five".