61213561 has 8 divisors (see below), whose sum is σ = 64226048. Its totient is φ = 58266000.

The previous prime is 61213547. The next prime is 61213571. The reversal of 61213561 is 16531216.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61213561 - 2⁷ = 61213433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61213531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14295 + ... + 18076.

It is an arithmetic number, because the mean of its divisors is an integer number (8028256).

Almost surely, 2^61213561 is an apocalyptic number.

61213561 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

61213561 is a deficient number, since it is larger than the sum of its proper divisors (3012487).

61213561 is a wasteful number, since it uses less digits than its factorization.

61213561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32463.

The product of its digits is 1080, while the sum is 25.

The square root of 61213561 is about 7823.9095725858. The cubic root of 61213561 is about 394.1085724646.

Adding to 61213561 its reverse (16531216), we get a palindrome (77744777).

The spelling of 61213561 in words is "sixty-one million, two hundred thirteen thousand, five hundred sixty-one".