61209621 has 32 divisors (see below), whose sum is σ = 104140800. Its totient is φ = 35141040.

The previous prime is 61209607. The next prime is 61209641. The reversal of 61209621 is 12690216.

It is not a de Polignac number, because 61209621 - 2⁷ = 61209493 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61209641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 220 + ... + 11066.

It is an arithmetic number, because the mean of its divisors is an integer number (3254400).

Almost surely, 2^61209621 is an apocalyptic number.

It is an amenable number.

61209621 is a deficient number, since it is larger than the sum of its proper divisors (42931179).

61209621 is a wasteful number, since it uses less digits than its factorization.

61209621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10886 (or 10880 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 61209621 is about 7823.6577762579. The cubic root of 61209621 is about 394.1001167070.

Adding to 61209621 its reverse (12690216), we get a palindrome (73899837).

The spelling of 61209621 in words is "sixty-one million, two hundred nine thousand, six hundred twenty-one".