61277778 has 12 divisors (see below), whose sum is σ = 132768558. Its totient is φ = 20425920.

The previous prime is 61277767. The next prime is 61277791. The reversal of 61277778 is 87777216.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 50168889 + 11108889 = 7083^2 + 3333^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1702143 + ... + 1702178.

Almost surely, 2^61277778 is an apocalyptic number.

61277778 is an abundant number, since it is smaller than the sum of its proper divisors (71490780).

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

61277778 is a wasteful number, since it uses less digits than its factorization.

61277778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3404329 (or 3404326 counting only the distinct ones).

The product of its digits is 230496, while the sum is 45.

The square root of 61277778 is about 7828.0123914056. The cubic root of 61277778 is about 394.2463394608.

The spelling of 61277778 in words is "sixty-one million, two hundred seventy-seven thousand, seven hundred seventy-eight".