61909897 has 4 divisors (see below), whose sum is σ = 70754176. Its totient is φ = 53065620.

The previous prime is 61909891. The next prime is 61909919. The reversal of 61909897 is 79890916.

61909897 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61909897 - 2¹⁹ = 61385609 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61909897.

It is not an unprimeable number, because it can be changed into a prime (61909891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4422129 + ... + 4422142.

It is an arithmetic number, because the mean of its divisors is an integer number (17688544).

Almost surely, 2^61909897 is an apocalyptic number.

It is an amenable number.

61909897 is a deficient number, since it is larger than the sum of its proper divisors (8844279).

61909897 is an equidigital number, since it uses as much as digits as its factorization.

61909897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8844278.

The product of its (nonzero) digits is 244944, while the sum is 49.

The square root of 61909897 is about 7868.2842475345. The cubic root of 61909897 is about 395.5973379563.

The spelling of 61909897 in words is "sixty-one million, nine hundred nine thousand, eight hundred ninety-seven".