61908921 has 8 divisors (see below), whose sum is σ = 91716960. Its totient is φ = 41272596.

The previous prime is 61908919. The next prime is 61908923. The reversal of 61908921 is 12980916.

It is an interprime number because it is at equal distance from previous prime (61908919) and next prime (61908923).

It is not a de Polignac number, because 61908921 - 2¹ = 61908919 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61908923) 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, 1146435 + ... + 1146488.

It is an arithmetic number, because the mean of its divisors is an integer number (11464620).

Almost surely, 2^61908921 is an apocalyptic number.

It is an amenable number.

61908921 is a deficient number, since it is larger than the sum of its proper divisors (29808039).

61908921 is a wasteful number, since it uses less digits than its factorization.

61908921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2292932 (or 2292926 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 61908921 is about 7868.2222261449. Note that the first 5 decimals coincide. The cubic root of 61908921 is about 395.5952591016.

The spelling of 61908921 in words is "sixty-one million, nine hundred eight thousand, nine hundred twenty-one".