121691505 has 64 divisors (see below), whose sum is σ = 224243712. Its totient is φ = 55883520.

The previous prime is 121691489. The next prime is 121691509. The reversal of 121691505 is 505196121.

It is not a de Polignac number, because 121691505 - 2⁴ = 121691489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121691509) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 192540 + ... + 193170.

It is an arithmetic number, because the mean of its divisors is an integer number (3503808).

Almost surely, 2^121691505 is an apocalyptic number.

121691505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121691505 is a deficient number, since it is larger than the sum of its proper divisors (102552207).

121691505 is a wasteful number, since it uses less digits than its factorization.

121691505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718.

The product of its (nonzero) digits is 2700, while the sum is 30.

The square root of 121691505 is about 11031.3872654349. The cubic root of 121691505 is about 495.5491711387.

The spelling of 121691505 in words is "one hundred twenty-one million, six hundred ninety-one thousand, five hundred five".