1231355550 has 24 divisors (see below), whose sum is σ = 3053762136. Its totient is φ = 328361440.

The previous prime is 1231355537. The next prime is 1231355561. The reversal of 1231355550 is 555531321.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4104369 + ... + 4104668.

It is an arithmetic number, because the mean of its divisors is an integer number (127240089).

Almost surely, 2^1231355550 is an apocalyptic number.

1231355550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1231355550 is an abundant number, since it is smaller than the sum of its proper divisors (1822406586).

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

1231355550 is a wasteful number, since it uses less digits than its factorization.

1231355550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8209052 (or 8209047 counting only the distinct ones).

The product of its (nonzero) digits is 11250, while the sum is 30.

The square root of 1231355550 is about 35090.6761120387. The cubic root of 1231355550 is about 1071.8347274122.

Adding to 1231355550 its reverse (555531321), we get a palindrome (1786886871).

The spelling of 1231355550 in words is "one billion, two hundred thirty-one million, three hundred fifty-five thousand, five hundred fifty".