121521447 has 6 divisors (see below), whose sum is σ = 175530992. Its totient is φ = 81014292.

The previous prime is 121521437. The next prime is 121521487. The reversal of 121521447 is 744125121.

121521447 is a `hidden beast` number, since 1 + 215 + 2 + 1 + 447 = 666.

It is not a de Polignac number, because 121521447 - 2⁷ = 121521319 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121521447.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121521427) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6751183 + ... + 6751200.

Almost surely, 2^121521447 is an apocalyptic number.

121521447 is a deficient number, since it is larger than the sum of its proper divisors (54009545).

121521447 is a wasteful number, since it uses less digits than its factorization.

121521447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13502389 (or 13502386 counting only the distinct ones).

The product of its digits is 2240, while the sum is 27.

The square root of 121521447 is about 11023.6766552725. The cubic root of 121521447 is about 495.3182281849.

Adding to 121521447 its reverse (744125121), we get a palindrome (865646568).

The spelling of 121521447 in words is "one hundred twenty-one million, five hundred twenty-one thousand, four hundred forty-seven".