391549296121 has 9 divisors (see below), whose sum is σ = 393169735983. Its totient is φ = 389935515240.

The previous prime is 391549296119. The next prime is 391549296211. The reversal of 391549296121 is 121692945193.

The square root of 391549296121 is 625739.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 326656828521 + 64892467600 = 571539^2 + 254740^2 .

It is not a de Polignac number, because 391549296121 - 2¹ = 391549296119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391549296521) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 169574115 + ... + 169576423.

Almost surely, 2^391549296121 is an apocalyptic number.

391549296121 is the 625739-th square number.

391549296121 is the 312870-th centered octagonal number.

It is an amenable number.

391549296121 is a deficient number, since it is larger than the sum of its proper divisors (1620439862).

391549296121 is an frugal number, since it uses more digits than its factorization.

391549296121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5160 (or 2580 counting only the distinct ones).

The product of its digits is 1049760, while the sum is 52.

The spelling of 391549296121 in words is "three hundred ninety-one billion, five hundred forty-nine million, two hundred ninety-six thousand, one hundred twenty-one".