61128921 has 24 divisors (see below), whose sum is σ = 97383360. Its totient is φ = 33983712.

The previous prime is 61128913. The next prime is 61128961. The reversal of 61128921 is 12982116.

It is a happy number.

It is not a de Polignac number, because 61128921 - 2³ = 61128913 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61128961) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 181 + ... + 11058.

It is an arithmetic number, because the mean of its divisors is an integer number (4057640).

Almost surely, 2^61128921 is an apocalyptic number.

It is an amenable number.

61128921 is a deficient number, since it is larger than the sum of its proper divisors (36254439).

61128921 is a wasteful number, since it uses less digits than its factorization.

61128921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11293 (or 11286 counting only the distinct ones).

The product of its digits is 1728, while the sum is 30.

The square root of 61128921 is about 7818.4986410436. The cubic root of 61128921 is about 393.9268440194.

The spelling of 61128921 in words is "sixty-one million, one hundred twenty-eight thousand, nine hundred twenty-one".