61899309 has 10 divisors (see below), whose sum is σ = 92466990. Its totient is φ = 41266152.

The previous prime is 61899307. The next prime is 61899337. The reversal of 61899309 is 90399816.

It can be written as a sum of positive squares in only one way, i.e., 57426084 + 4473225 = 7578^2 + 2115^2 .

It is not a de Polignac number, because 61899309 - 2¹ = 61899307 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61899301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 382014 + ... + 382175.

It is an arithmetic number, because the mean of its divisors is an integer number (9246699).

Almost surely, 2^61899309 is an apocalyptic number.

It is an amenable number.

61899309 is a deficient number, since it is larger than the sum of its proper divisors (30567681).

61899309 is an equidigital number, since it uses as much as digits as its factorization.

61899309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764201 (or 764192 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 61899309 is about 7867.6113910132. The cubic root of 61899309 is about 395.5747846241.

The spelling of 61899309 in words is "sixty-one million, eight hundred ninety-nine thousand, three hundred nine".