61199999 has 4 divisors (see below), whose sum is σ = 69942864. Its totient is φ = 52457136.

The previous prime is 61199993. The next prime is 61200023. The reversal of 61199999 is 99999116.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61199999 is a prime.

It is a Duffinian number.

61199999 is a modest number, since divided by 9999 gives 6119 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 61199999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61199993) 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, 4371422 + ... + 4371435.

It is an arithmetic number, because the mean of its divisors is an integer number (17485716).

Almost surely, 2^61199999 is an apocalyptic number.

61199999 is a deficient number, since it is larger than the sum of its proper divisors (8742865).

61199999 is an equidigital number, since it uses as much as digits as its factorization.

61199999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8742864.

The product of its digits is 354294, while the sum is 53.

The square root of 61199999 is about 7823.0428223294. The cubic root of 61199999 is about 394.0794651059.

The spelling of 61199999 in words is "sixty-one million, one hundred ninety-nine thousand, nine hundred ninety-nine".