5155321221 has 20 divisors (see below), whose sum is σ = 7704348300. Its totient is φ = 3435457536.

The previous prime is 5155321187. The next prime is 5155321261. The reversal of 5155321221 is 1221235515.

5155321221 is a `hidden beast` number, since 5 + 1 + 5 + 532 + 122 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 813960900 + 4341360321 = 28530^2 + 65889^2 .

It is not a de Polignac number, because 5155321221 - 2²³ = 5146932613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5155321261) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 205975 + ... + 229643.

It is an arithmetic number, because the mean of its divisors is an integer number (385217415).

Almost surely, 2^5155321221 is an apocalyptic number.

It is an amenable number.

5155321221 is a deficient number, since it is larger than the sum of its proper divisors (2549027079).

5155321221 is a wasteful number, since it uses less digits than its factorization.

5155321221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26370 (or 26361 counting only the distinct ones).

The product of its digits is 3000, while the sum is 27.

The square root of 5155321221 is about 71800.5656036218. The cubic root of 5155321221 is about 1727.5020718845.

Adding to 5155321221 its reverse (1221235515), we get a palindrome (6376556736).

The spelling of 5155321221 in words is "five billion, one hundred fifty-five million, three hundred twenty-one thousand, two hundred twenty-one".