61563813 has 4 divisors (see below), whose sum is σ = 82085088. Its totient is φ = 41042540.

The previous prime is 61563811. The next prime is 61563871. The reversal of 61563813 is 31836516.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61563813 - 2¹ = 61563811 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61563811) 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, 10260633 + ... + 10260638.

It is an arithmetic number, because the mean of its divisors is an integer number (20521272).

Almost surely, 2^61563813 is an apocalyptic number.

It is an amenable number.

61563813 is a deficient number, since it is larger than the sum of its proper divisors (20521275).

61563813 is a wasteful number, since it uses less digits than its factorization.

61563813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20521274.

The product of its digits is 12960, while the sum is 33.

The square root of 61563813 is about 7846.2610841088. The cubic root of 61563813 is about 394.8588140397.

The spelling of 61563813 in words is "sixty-one million, five hundred sixty-three thousand, eight hundred thirteen".