7478428321661 has 24 divisors (see below), whose sum is σ = 8846307909432. Its totient is φ = 6293759155200.

The previous prime is 7478428321597. The next prime is 7478428321667. The reversal of 7478428321661 is 1661238248747.

It can be written as a sum of positive squares in 4 ways, for example, as 1593830500900 + 5884597820761 = 1262470^2 + 2425819^2 .

It is not a de Polignac number, because 7478428321661 - 2⁶ = 7478428321597 is a prime.

It is a super-2 number, since 2×7478428321661² (a number of 27 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 7478428321661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7478428321667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29674520 + ... + 29925473.

It is an arithmetic number, because the mean of its divisors is an integer number (368596162893).

Almost surely, 2^{7478428321661} is an apocalyptic number.

It is an amenable number.

7478428321661 is a deficient number, since it is larger than the sum of its proper divisors (1367879587771).

7478428321661 is a wasteful number, since it uses less digits than its factorization.

7478428321661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59600093 (or 59600082 counting only the distinct ones).

The product of its digits is 21676032, while the sum is 59.

The spelling of 7478428321661 in words is "seven trillion, four hundred seventy-eight billion, four hundred twenty-eight million, three hundred twenty-one thousand, six hundred sixty-one".