51215201561855 has 4 divisors (see below), whose sum is σ = 61458241874232. Its totient is φ = 40972161249480.

The previous prime is 51215201561831. The next prime is 51215201561861. The reversal of 51215201561855 is 55816510251215.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 51215201561855 - 2²⁴ = 51215184784639 is a prime.

It is a super-3 number, since 3×51215201561855³ (a number of 42 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5121520156181 + ... + 5121520156190.

It is an arithmetic number, because the mean of its divisors is an integer number (15364560468558).

Almost surely, 2^{51215201561855} is an apocalyptic number.

51215201561855 is a deficient number, since it is larger than the sum of its proper divisors (10243040312377).

51215201561855 is a wasteful number, since it uses less digits than its factorization.

51215201561855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10243040312376.

The product of its (nonzero) digits is 600000, while the sum is 47.

The spelling of 51215201561855 in words is "fifty-one trillion, two hundred fifteen billion, two hundred one million, five hundred sixty-one thousand, eight hundred fifty-five".