61216641 has 20 divisors (see below), whose sum is σ = 91841904. Its totient is φ = 40635000.

The previous prime is 61216637. The next prime is 61216657. The reversal of 61216641 is 14661216.

61216641 is a `hidden beast` number, since 6 + 1 + 2 + 16 + 641 = 666.

It is not a de Polignac number, because 61216641 - 2² = 61216637 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (61216601) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18826 + ... + 21836.

Almost surely, 2^61216641 is an apocalyptic number.

It is an amenable number.

61216641 is a deficient number, since it is larger than the sum of its proper divisors (30625263).

61216641 is a wasteful number, since it uses less digits than its factorization.

61216641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3274 (or 3265 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 61216641 is about 7824.1064026507. The cubic root of 61216641 is about 394.1151822965.

Adding to 61216641 its reverse (14661216), we get a palindrome (75877857).

The spelling of 61216641 in words is "sixty-one million, two hundred sixteen thousand, six hundred forty-one".