121431555 has 120 divisors (see below), whose sum is σ = 263189520. Its totient is φ = 53343360.

The previous prime is 121431553. The next prime is 121431587. The reversal of 121431555 is 555134121.

It is not a de Polignac number, because 121431555 - 2¹ = 121431553 is a prime.

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

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121431551) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 575400 + ... + 575610.

It is an arithmetic number, because the mean of its divisors is an integer number (2193246).

Almost surely, 2^121431555 is an apocalyptic number.

121431555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121431555 is an abundant number, since it is smaller than the sum of its proper divisors (141757965).

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

121431555 is a wasteful number, since it uses less digits than its factorization.

121431555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271 (or 255 counting only the distinct ones).

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

The square root of 121431555 is about 11019.5986769029. The cubic root of 121431555 is about 495.1960655804.

Adding to 121431555 its reverse (555134121), we get a palindrome (676565676).

The spelling of 121431555 in words is "one hundred twenty-one million, four hundred thirty-one thousand, five hundred fifty-five".