61778945 has 16 divisors (see below), whose sum is σ = 75195648. Its totient is φ = 48721920.

The previous prime is 61778929. The next prime is 61778947. The reversal of 61778945 is 54987716.

It is not a de Polignac number, because 61778945 - 2⁴ = 61778929 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 61778945.

It is not an unprimeable number, because it can be changed into a prime (61778947) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 168152 + ... + 168518.

It is an arithmetic number, because the mean of its divisors is an integer number (4699728).

Almost surely, 2^61778945 is an apocalyptic number.

It is an amenable number.

61778945 is a deficient number, since it is larger than the sum of its proper divisors (13416703).

61778945 is a wasteful number, since it uses less digits than its factorization.

61778945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760.

The product of its digits is 423360, while the sum is 47.

The square root of 61778945 is about 7859.9583332229. The cubic root of 61778945 is about 395.3182181731.

The spelling of 61778945 in words is "sixty-one million, seven hundred seventy-eight thousand, nine hundred forty-five".