61376778 has 20 divisors (see below), whose sum is σ = 137529810. Its totient is φ = 20458872.

The previous prime is 61376771. The next prime is 61376801. The reversal of 61376778 is 87767316.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 57562569 + 3814209 = 7587^2 + 1953^2 .

It is a super-2 number, since 2×61376778² = 7534217755322568, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61376771) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 189273 + ... + 189596.

Almost surely, 2^61376778 is an apocalyptic number.

61376778 is an abundant number, since it is smaller than the sum of its proper divisors (76153032).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61376778 is a wasteful number, since it uses less digits than its factorization.

61376778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378883 (or 378874 counting only the distinct ones).

The product of its digits is 296352, while the sum is 45.

The square root of 61376778 is about 7834.3332836943. Note that the first 3 decimals coincide. The cubic root of 61376778 is about 394.4585392100.

The spelling of 61376778 in words is "sixty-one million, three hundred seventy-six thousand, seven hundred seventy-eight".