121555071 has 12 divisors (see below), whose sum is σ = 191541480. Its totient is φ = 73669680.

The previous prime is 121555013. The next prime is 121555073. The reversal of 121555071 is 170555121.

121555071 is a `hidden beast` number, since 1 + 2 + 155 + 507 + 1 = 666.

It is not a de Polignac number, because 121555071 - 2¹⁰ = 121554047 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121555073) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 613816 + ... + 614013.

It is an arithmetic number, because the mean of its divisors is an integer number (15961790).

Almost surely, 2^121555071 is an apocalyptic number.

121555071 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

121555071 is a deficient number, since it is larger than the sum of its proper divisors (69986409).

121555071 is a wasteful number, since it uses less digits than its factorization.

121555071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1227846 (or 1227843 counting only the distinct ones).

The product of its (nonzero) digits is 1750, while the sum is 27.

The square root of 121555071 is about 11025.2016308093. The cubic root of 121555071 is about 495.3639074860.

Subtracting 121555071 from its reverse (170555121), we obtain a triangular number (49000050 = T₉₈₉₉).

The spelling of 121555071 in words is "one hundred twenty-one million, five hundred fifty-five thousand, seventy-one".