55403121321 has 24 divisors (see below), whose sum is σ = 80629403400. Its totient is φ = 36657662976.

The previous prime is 55403121299. The next prime is 55403121343. The reversal of 55403121321 is 12312130455.

It is an interprime number because it is at equal distance from previous prime (55403121299) and next prime (55403121343).

It can be written as a sum of positive squares in 4 ways, for example, as 11288000025 + 44115121296 = 106245^2 + 210036^2 .

It is not a de Polignac number, because 55403121321 - 2¹⁴ = 55403104937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55403121721) 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, 1696281 + ... + 1728633.

It is an arithmetic number, because the mean of its divisors is an integer number (3359558475).

Almost surely, 2^55403121321 is an apocalyptic number.

It is an amenable number.

55403121321 is a deficient number, since it is larger than the sum of its proper divisors (25226282079).

55403121321 is a wasteful number, since it uses less digits than its factorization.

55403121321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33785 (or 33782 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

Adding to 55403121321 its reverse (12312130455), we get a palindrome (67715251776).

The spelling of 55403121321 in words is "fifty-five billion, four hundred three million, one hundred twenty-one thousand, three hundred twenty-one".