505656121 has 4 divisors (see below), whose sum is σ = 506930212. Its totient is φ = 504382032.

The previous prime is 505656119. The next prime is 505656191. The reversal of 505656121 is 121656505.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 291180096 + 214476025 = 17064^2 + 14645^2 .

It is a cyclic number.

It is not a de Polignac number, because 505656121 - 2¹ = 505656119 is a prime.

It is a super-2 number, since 2×505656121² = 511376225409533282, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (505656191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 636450 + ... + 637243.

It is an arithmetic number, because the mean of its divisors is an integer number (126732553).

Almost surely, 2^505656121 is an apocalyptic number.

It is an amenable number.

505656121 is a deficient number, since it is larger than the sum of its proper divisors (1274091).

505656121 is a wasteful number, since it uses less digits than its factorization.

505656121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1274090.

The product of its (nonzero) digits is 9000, while the sum is 31.

The square root of 505656121 is about 22486.7988161944. The cubic root of 505656121 is about 796.6821552595.

The spelling of 505656121 in words is "five hundred five million, six hundred fifty-six thousand, one hundred twenty-one".