61521369 has 16 divisors (see below), whose sum is σ = 100958592. Its totient is φ = 32450688.

The previous prime is 61521359. The next prime is 61521379. The reversal of 61521369 is 96312516.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (61521359) and next prime (61521379).

It is not a de Polignac number, because 61521369 - 2⁵ = 61521337 is a prime.

It is a super-2 number, since 2×61521369² = 7569757687268322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (61521319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 112404 + ... + 112949.

It is an arithmetic number, because the mean of its divisors is an integer number (6309912).

Almost surely, 2^61521369 is an apocalyptic number.

It is an amenable number.

61521369 is a deficient number, since it is larger than the sum of its proper divisors (39437223).

61521369 is a wasteful number, since it uses less digits than its factorization.

61521369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225376.

The product of its digits is 9720, while the sum is 33.

The square root of 61521369 is about 7843.5558900285. Note that the first 3 decimals coincide. The cubic root of 61521369 is about 394.7680505450.

The spelling of 61521369 in words is "sixty-one million, five hundred twenty-one thousand, three hundred sixty-nine".