61764021 has 12 divisors (see below), whose sum is σ = 97325280. Its totient is φ = 37432680.

The previous prime is 61764013. The next prime is 61764023. The reversal of 61764021 is 12046716.

61764021 is a `hidden beast` number, since 6 + 17 + 640 + 2 + 1 = 666.

It is not a de Polignac number, because 61764021 - 2³ = 61764013 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 (61764023) 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, 311841 + ... + 312038.

It is an arithmetic number, because the mean of its divisors is an integer number (8110440).

Almost surely, 2^61764021 is an apocalyptic number.

It is an amenable number.

61764021 is a deficient number, since it is larger than the sum of its proper divisors (35561259).

61764021 is a wasteful number, since it uses less digits than its factorization.

61764021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 623896 (or 623893 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 61764021 is about 7859.0089069806. The cubic root of 61764021 is about 395.2863831403.

The spelling of 61764021 in words is "sixty-one million, seven hundred sixty-four thousand, twenty-one".