61521823 has 4 divisors (see below), whose sum is σ = 67114728. Its totient is φ = 55928920.

The previous prime is 61521799. The next prime is 61521839. The reversal of 61521823 is 32812516.

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

It is a cyclic number.

It is not a de Polignac number, because 61521823 - 2¹⁷ = 61390751 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61521791 and 61521800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61524823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2796436 + ... + 2796457.

It is an arithmetic number, because the mean of its divisors is an integer number (16778682).

Almost surely, 2^61521823 is an apocalyptic number.

61521823 is a deficient number, since it is larger than the sum of its proper divisors (5592905).

61521823 is a wasteful number, since it uses less digits than its factorization.

61521823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5592904.

The product of its digits is 2880, while the sum is 28.

The square root of 61521823 is about 7843.5848309303. The cubic root of 61521823 is about 394.7690216127.

The spelling of 61521823 in words is "sixty-one million, five hundred twenty-one thousand, eight hundred twenty-three".