61717621 has 8 divisors (see below), whose sum is σ = 72809984. Its totient is φ = 51194160.

The previous prime is 61717613. The next prime is 61717697. The reversal of 61717621 is 12671716.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61717621 - 2³ = 61717613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61717321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 141990 + ... + 142423.

It is an arithmetic number, because the mean of its divisors is an integer number (9101248).

Almost surely, 2^61717621 is an apocalyptic number.

It is an amenable number.

61717621 is a deficient number, since it is larger than the sum of its proper divisors (11092363).

61717621 is a wasteful number, since it uses less digits than its factorization.

61717621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284451.

The product of its digits is 3528, while the sum is 31.

The square root of 61717621 is about 7856.0563261728. The cubic root of 61717621 is about 395.1873725149.

The spelling of 61717621 in words is "sixty-one million, seven hundred seventeen thousand, six hundred twenty-one".