121577661 has 12 divisors (see below), whose sum is σ = 175928220. Its totient is φ = 80905920.

The previous prime is 121577611. The next prime is 121577663. The reversal of 121577661 is 166775121.

121577661 is a `hidden beast` number, since 1 + 21 + 577 + 6 + 61 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 81812025 + 39765636 = 9045^2 + 6306^2 .

It is not a de Polignac number, because 121577661 - 2¹¹ = 121575613 is a prime.

It is a super-2 number, since 2×121577661² = 29562255308461842, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121577663) 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, 6750 + ... + 16991.

It is an arithmetic number, because the mean of its divisors is an integer number (14660685).

Almost surely, 2^121577661 is an apocalyptic number.

It is an amenable number.

121577661 is a deficient number, since it is larger than the sum of its proper divisors (54350559).

121577661 is a wasteful number, since it uses less digits than its factorization.

121577661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24316 (or 24313 counting only the distinct ones).

The product of its digits is 17640, while the sum is 36.

The square root of 121577661 is about 11026.2260542762. The cubic root of 121577661 is about 495.3945920074.

The spelling of 121577661 in words is "one hundred twenty-one million, five hundred seventy-seven thousand, six hundred sixty-one".