61537821 has 8 divisors (see below), whose sum is σ = 84697344. Its totient is φ = 39701760.

The previous prime is 61537769. The next prime is 61537829. The reversal of 61537821 is 12873516.

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

It is not a de Polignac number, because 61537821 - 2⁹ = 61537309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61537829) 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 7 ways as a sum of consecutive naturals, for example, 330756 + ... + 330941.

It is an arithmetic number, because the mean of its divisors is an integer number (10587168).

Almost surely, 2^61537821 is an apocalyptic number.

It is an amenable number.

61537821 is a deficient number, since it is larger than the sum of its proper divisors (23159523).

61537821 is a wasteful number, since it uses less digits than its factorization.

61537821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661731.

The product of its digits is 10080, while the sum is 33.

The square root of 61537821 is about 7844.6045789447. The cubic root of 61537821 is about 394.8032369375.

The spelling of 61537821 in words is "sixty-one million, five hundred thirty-seven thousand, eight hundred twenty-one".