51217867221 has 8 divisors (see below), whose sum is σ = 68292197664. Its totient is φ = 34144390800.

The previous prime is 51217867219. The next prime is 51217867273. The reversal of 51217867221 is 12276871215.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51217867221 - 2¹ = 51217867219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51217867201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57226 + ... + 325131.

It is an arithmetic number, because the mean of its divisors is an integer number (8536524708).

Almost surely, 2^51217867221 is an apocalyptic number.

It is an amenable number.

51217867221 is a deficient number, since it is larger than the sum of its proper divisors (17074330443).

51217867221 is a wasteful number, since it uses less digits than its factorization.

51217867221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427011.

The product of its digits is 94080, while the sum is 42.

The spelling of 51217867221 in words is "fifty-one billion, two hundred seventeen million, eight hundred sixty-seven thousand, two hundred twenty-one".