61878545 has 4 divisors (see below), whose sum is σ = 74254260. Its totient is φ = 49502832.

The previous prime is 61878539. The next prime is 61878563. The reversal of 61878545 is 54587816.

It is a happy number.

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 15311569 + 46566976 = 3913^2 + 6824^2 .

It is a cyclic number.

It is not a de Polignac number, because 61878545 - 2⁴ = 61878529 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 61878496 and 61878505.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6187850 + ... + 6187859.

It is an arithmetic number, because the mean of its divisors is an integer number (18563565).

Almost surely, 2^61878545 is an apocalyptic number.

It is an amenable number.

61878545 is a deficient number, since it is larger than the sum of its proper divisors (12375715).

61878545 is a wasteful number, since it uses less digits than its factorization.

61878545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12375714.

The product of its digits is 268800, while the sum is 44.

The square root of 61878545 is about 7866.2916930406. The cubic root of 61878545 is about 395.5305480860.

The spelling of 61878545 in words is "sixty-one million, eight hundred seventy-eight thousand, five hundred forty-five".