61961887 has 4 divisors (see below), whose sum is σ = 66728200. Its totient is φ = 57195576.

The previous prime is 61961873. The next prime is 61961897. The reversal of 61961887 is 78816916.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61961887 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 (61961827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2383137 + ... + 2383162.

It is an arithmetic number, because the mean of its divisors is an integer number (16682050).

Almost surely, 2^61961887 is an apocalyptic number.

61961887 is a deficient number, since it is larger than the sum of its proper divisors (4766313).

61961887 is a wasteful number, since it uses less digits than its factorization.

61961887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4766312.

The product of its digits is 145152, while the sum is 46.

The square root of 61961887 is about 7871.5873240408. The cubic root of 61961887 is about 395.7080437404.

The spelling of 61961887 in words is "sixty-one million, nine hundred sixty-one thousand, eight hundred eighty-seven".