61890749 has 4 divisors (see below), whose sum is σ = 61910940. Its totient is φ = 61870560.

The previous prime is 61890707. The next prime is 61890757. The reversal of 61890749 is 94709816.

61890749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 20994724 + 40896025 = 4582^2 + 6395^2 .

It is a cyclic number.

It is not a de Polignac number, because 61890749 - 2¹⁶ = 61825213 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61890779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4442 + ... + 11979.

It is an arithmetic number, because the mean of its divisors is an integer number (15477735).

Almost surely, 2^61890749 is an apocalyptic number.

It is an amenable number.

61890749 is a deficient number, since it is larger than the sum of its proper divisors (20191).

61890749 is a wasteful number, since it uses less digits than its factorization.

61890749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20190.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 61890749 is about 7867.0673697382. The cubic root of 61890749 is about 395.5565492226.

The spelling of 61890749 in words is "sixty-one million, eight hundred ninety thousand, seven hundred forty-nine".