51221534 has 24 divisors (see below), whose sum is σ = 95086800. Its totient is φ = 20262528.

The previous prime is 51221531. The next prime is 51221537. The reversal of 51221534 is 43512215.

It is an interprime number because it is at equal distance from previous prime (51221531) and next prime (51221537).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51221531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8459 + ... + 13190.

It is an arithmetic number, because the mean of its divisors is an integer number (3961950).

Almost surely, 2^51221534 is an apocalyptic number.

51221534 is a deficient number, since it is larger than the sum of its proper divisors (43865266).

51221534 is a wasteful number, since it uses less digits than its factorization.

51221534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21684 (or 21671 counting only the distinct ones).

The product of its digits is 1200, while the sum is 23.

The square root of 51221534 is about 7156.9221038097. The cubic root of 51221534 is about 371.3791577122.

Adding to 51221534 its reverse (43512215), we get a palindrome (94733749).

The spelling of 51221534 in words is "fifty-one million, two hundred twenty-one thousand, five hundred thirty-four".