61561642 has 4 divisors (see below), whose sum is σ = 92342466. Its totient is φ = 30780820.

The previous prime is 61561631. The next prime is 61561649. The reversal of 61561642 is 24616516.

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

It can be written as a sum of positive squares in only one way, i.e., 54597321 + 6964321 = 7389^2 + 2639^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (61561649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15390409 + ... + 15390412.

Almost surely, 2^61561642 is an apocalyptic number.

61561642 is a deficient number, since it is larger than the sum of its proper divisors (30780824).

61561642 is a wasteful number, since it uses less digits than its factorization.

61561642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30780823.

The product of its digits is 8640, while the sum is 31.

The square root of 61561642 is about 7846.1227367407. The cubic root of 61561642 is about 394.8541725221.

The spelling of 61561642 in words is "sixty-one million, five hundred sixty-one thousand, six hundred forty-two".