61778523 has 4 divisors (see below), whose sum is σ = 82371368. Its totient is φ = 41185680.

The previous prime is 61778501. The next prime is 61778537. The reversal of 61778523 is 32587716.

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

It is not a de Polignac number, because 61778523 - 2²¹ = 59681371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61578523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10296418 + ... + 10296423.

It is an arithmetic number, because the mean of its divisors is an integer number (20592842).

Almost surely, 2^61778523 is an apocalyptic number.

61778523 is a deficient number, since it is larger than the sum of its proper divisors (20592845).

61778523 is a wasteful number, since it uses less digits than its factorization.

61778523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20592844.

The product of its digits is 70560, while the sum is 39.

The square root of 61778523 is about 7859.9314882510. The cubic root of 61778523 is about 395.3173180570.

The spelling of 61778523 in words is "sixty-one million, seven hundred seventy-eight thousand, five hundred twenty-three".