51187223642 has 4 divisors (see below), whose sum is σ = 76780835466. Its totient is φ = 25593611820.

The previous prime is 51187223641. The next prime is 51187223651. The reversal of 51187223642 is 24632278115.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24632278115 = 5 ⋅4926455623.

It can be written as a sum of positive squares in only one way, i.e., 41669465161 + 9517758481 = 204131^2 + 97559^2 .

It is a super-2 number, since 2×51187223642² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51187223642.

It is not an unprimeable number, because it can be changed into a prime (51187223641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12796805909 + ... + 12796805912.

Almost surely, 2^51187223642 is an apocalyptic number.

51187223642 is a deficient number, since it is larger than the sum of its proper divisors (25593611824).

51187223642 is a wasteful number, since it uses less digits than its factorization.

51187223642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25593611823.

The product of its digits is 161280, while the sum is 41.

The spelling of 51187223642 in words is "fifty-one billion, one hundred eighty-seven million, two hundred twenty-three thousand, six hundred forty-two".