61668531 has 6 divisors (see below), whose sum is σ = 89076780. Its totient is φ = 41112348.

The previous prime is 61668527. The next prime is 61668539. The reversal of 61668531 is 13586616.

It is a happy number.

61668531 is a `hidden beast` number, since 61 + 6 + 68 + 531 = 666.

It is not a de Polignac number, because 61668531 - 2² = 61668527 is a prime.

It is a super-2 number, since 2×61668531² = 7606015431395922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (61668539) 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 5 ways as a sum of consecutive naturals, for example, 3426021 + ... + 3426038.

It is an arithmetic number, because the mean of its divisors is an integer number (14846130).

Almost surely, 2^61668531 is an apocalyptic number.

61668531 is a deficient number, since it is larger than the sum of its proper divisors (27408249).

61668531 is a wasteful number, since it uses less digits than its factorization.

61668531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6852065 (or 6852062 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 61668531 is about 7852.9313635101. The cubic root of 61668531 is about 395.0825677953.

The spelling of 61668531 in words is "sixty-one million, six hundred sixty-eight thousand, five hundred thirty-one".