61528021 has 4 divisors (see below), whose sum is σ = 61556544. Its totient is φ = 61499500.

The previous prime is 61528009. The next prime is 61528037. The reversal of 61528021 is 12082516.

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 61528021 - 2⁵ = 61527989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61528081) 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 3 ways as a sum of consecutive naturals, for example, 10735 + ... + 15436.

It is an arithmetic number, because the mean of its divisors is an integer number (15389136).

Almost surely, 2^61528021 is an apocalyptic number.

It is an amenable number.

61528021 is a deficient number, since it is larger than the sum of its proper divisors (28523).

61528021 is a wasteful number, since it uses less digits than its factorization.

61528021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28522.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 61528021 is about 7843.9799209330. The cubic root of 61528021 is about 394.7822781349.

The spelling of 61528021 in words is "sixty-one million, five hundred twenty-eight thousand, twenty-one".