51216260621 has 8 divisors (see below), whose sum is σ = 54382611384. Its totient is φ = 48066979840.

The previous prime is 51216260611. The next prime is 51216260629. The reversal of 51216260621 is 12606261215.

It can be written as a sum of positive squares in 4 ways, for example, as 2025900100 + 49190360521 = 45010^2 + 221789^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51216260621 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 (51216260629) 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, 4261310 + ... + 4273311.

It is an arithmetic number, because the mean of its divisors is an integer number (6797826423).

Almost surely, 2^51216260621 is an apocalyptic number.

It is an amenable number.

51216260621 is a deficient number, since it is larger than the sum of its proper divisors (3166350763).

51216260621 is a wasteful number, since it uses less digits than its factorization.

51216260621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8534991.

The product of its (nonzero) digits is 8640, while the sum is 32.

The spelling of 51216260621 in words is "fifty-one billion, two hundred sixteen million, two hundred sixty thousand, six hundred twenty-one".