7721015073138 has 12 divisors (see below), whose sum is σ = 16728865991838. Its totient is φ = 2573671691040.

The previous prime is 7721015073127. The next prime is 7721015073151. The reversal of 7721015073138 is 8313705101277.

7721015073138 is a `hidden beast` number, since 7 + 7 + 2 + 1 + 0 + 1 + 507 + 3 + 138 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3950144325009 + 3770870748129 = 1987497^2 + 1941873^2 .

It is a super-2 number, since 2×7721015073138² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 7721015073093 and 7721015073102.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214472640903 + ... + 214472640938.

Almost surely, 2^{7721015073138} is an apocalyptic number.

7721015073138 is an abundant number, since it is smaller than the sum of its proper divisors (9007850918700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7721015073138 is a wasteful number, since it uses less digits than its factorization.

7721015073138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428945281849 (or 428945281846 counting only the distinct ones).

The product of its (nonzero) digits is 246960, while the sum is 45.

The spelling of 7721015073138 in words is "seven trillion, seven hundred twenty-one billion, fifteen million, seventy-three thousand, one hundred thirty-eight".