51021331355 has 4 divisors (see below), whose sum is σ = 61225597632. Its totient is φ = 40817065080.

The previous prime is 51021331321. The next prime is 51021331357. The reversal of 51021331355 is 55313312015.

It is a happy number.

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

It is not a de Polignac number, because 51021331355 - 2¹⁶ = 51021265819 is a prime.

It is a super-2 number, since 2×51021331355² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51021331357) 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, 5102133131 + ... + 5102133140.

It is an arithmetic number, because the mean of its divisors is an integer number (15306399408).

Almost surely, 2^51021331355 is an apocalyptic number.

51021331355 is a deficient number, since it is larger than the sum of its proper divisors (10204266277).

51021331355 is a wasteful number, since it uses less digits than its factorization.

51021331355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10204266276.

The product of its (nonzero) digits is 6750, while the sum is 29.

The spelling of 51021331355 in words is "fifty-one billion, twenty-one million, three hundred thirty-one thousand, three hundred fifty-five".