51634506221 has 4 divisors (see below), whose sum is σ = 51720708000. Its totient is φ = 51548304444.

The previous prime is 51634506211. The next prime is 51634506227. The reversal of 51634506221 is 12260543615.

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: 12260543615 = 5 ⋅2452108723.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51634506221 is a prime.

It is a super-2 number, since 2×51634506221² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51634506227) 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, 43099991 + ... + 43101188.

It is an arithmetic number, because the mean of its divisors is an integer number (12930177000).

Almost surely, 2^51634506221 is an apocalyptic number.

It is an amenable number.

51634506221 is a deficient number, since it is larger than the sum of its proper divisors (86201779).

51634506221 is an equidigital number, since it uses as much as digits as its factorization.

51634506221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86201778.

The product of its (nonzero) digits is 43200, while the sum is 35.

The spelling of 51634506221 in words is "fifty-one billion, six hundred thirty-four million, five hundred six thousand, two hundred twenty-one".