121506105 has 16 divisors (see below), whose sum is σ = 222182784. Its totient is φ = 55545600.

The previous prime is 121506103. The next prime is 121506109. The reversal of 121506105 is 501605121.

It is not a de Polignac number, because 121506105 - 2¹ = 121506103 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (121506103) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 578496 + ... + 578705.

It is an arithmetic number, because the mean of its divisors is an integer number (13886424).

Almost surely, 2^121506105 is an apocalyptic number.

121506105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121506105 is a deficient number, since it is larger than the sum of its proper divisors (100676679).

121506105 is a wasteful number, since it uses less digits than its factorization.

121506105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1157216.

The product of its (nonzero) digits is 300, while the sum is 21.

The square root of 121506105 is about 11022.9807674694. The cubic root of 121506105 is about 495.2973827779.

The spelling of 121506105 in words is "one hundred twenty-one million, five hundred six thousand, one hundred five".