61550021 has 8 divisors (see below), whose sum is σ = 66683904. Its totient is φ = 56473200.

The previous prime is 61549967. The next prime is 61550033. The reversal of 61550021 is 12005516.

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 61550021 - 2¹⁰ = 61548997 is a prime.

It is a super-3 number, since 3×61550021³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61549975 and 61550002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61552021) 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, 12005 + ... + 16346.

It is an arithmetic number, because the mean of its divisors is an integer number (8335488).

Almost surely, 2^61550021 is an apocalyptic number.

It is an amenable number.

61550021 is a deficient number, since it is larger than the sum of its proper divisors (5133883).

61550021 is a wasteful number, since it uses less digits than its factorization.

61550021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28531.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 61550021 is about 7845.3821449309. The cubic root of 61550021 is about 394.8293253990.

Adding to 61550021 its reverse (12005516), we get a palindrome (73555537).

The spelling of 61550021 in words is "sixty-one million, five hundred fifty thousand, twenty-one".