67749561 has 16 divisors (see below), whose sum is σ = 109494720. Its totient is φ = 41060160.

The previous prime is 67749551. The next prime is 67749571. The reversal of 67749561 is 16594776.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (67749551) and next prime (67749571).

It is not a de Polignac number, because 67749561 - 2⁷ = 67749433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (67749551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113760 + ... + 114353.

It is an arithmetic number, because the mean of its divisors is an integer number (6843420).

Almost surely, 2^67749561 is an apocalyptic number.

It is an amenable number.

67749561 is a deficient number, since it is larger than the sum of its proper divisors (41745159).

67749561 is a wasteful number, since it uses less digits than its factorization.

67749561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228133 (or 228127 counting only the distinct ones).

The product of its digits is 317520, while the sum is 45.

The square root of 67749561 is about 8231.0121491831. The cubic root of 67749561 is about 407.6638125943.

The spelling of 67749561 in words is "sixty-seven million, seven hundred forty-nine thousand, five hundred sixty-one".