61767661 has 4 divisors (see below), whose sum is σ = 62379324. Its totient is φ = 61156000.

The previous prime is 61767653. The next prime is 61767677. The reversal of 61767661 is 16676716.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 60372900 + 1394761 = 7770^2 + 1181^2 .

It is a cyclic number.

It is not a de Polignac number, because 61767661 - 2³ = 61767653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61767611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 305680 + ... + 305881.

It is an arithmetic number, because the mean of its divisors is an integer number (15594831).

Almost surely, 2^61767661 is an apocalyptic number.

It is an amenable number.

61767661 is a deficient number, since it is larger than the sum of its proper divisors (611663).

61767661 is a wasteful number, since it uses less digits than its factorization.

61767661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 611662.

The product of its digits is 63504, while the sum is 40.

The square root of 61767661 is about 7859.2404849324. The cubic root of 61767661 is about 395.2941482552.

The spelling of 61767661 in words is "sixty-one million, seven hundred sixty-seven thousand, six hundred sixty-one".