61668997 has 4 divisors (see below), whose sum is σ = 66412780. Its totient is φ = 56925216.

The previous prime is 61668991. The next prime is 61669001. The reversal of 61668997 is 79986616.

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 21104836 + 40564161 = 4594^2 + 6369^2 .

It is a cyclic number.

It is not a de Polignac number, because 61668997 - 2³ = 61668989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61668991) 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, 2371872 + ... + 2371897.

It is an arithmetic number, because the mean of its divisors is an integer number (16603195).

Almost surely, 2^61668997 is an apocalyptic number.

It is an amenable number.

61668997 is a deficient number, since it is larger than the sum of its proper divisors (4743783).

61668997 is a wasteful number, since it uses less digits than its factorization.

61668997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4743782.

The product of its digits is 979776, while the sum is 52.

The square root of 61668997 is about 7852.9610339031. The cubic root of 61668997 is about 395.0835629436.

The spelling of 61668997 in words is "sixty-one million, six hundred sixty-eight thousand, nine hundred ninety-seven".