7661921 has 16 divisors (see below), whose sum is σ = 8553600. Its totient is φ = 6830208.

The previous prime is 7661903. The next prime is 7661939. The reversal of 7661921 is 1291667.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (7661903) and next prime (7661939).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7661921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (7661981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38795 + ... + 38991.

It is an arithmetic number, because the mean of its divisors is an integer number (534600).

Almost surely, 2^7661921 is an apocalyptic number.

It is an amenable number.

7661921 is a deficient number, since it is larger than the sum of its proper divisors (891679).

7661921 is a wasteful number, since it uses less digits than its factorization.

7661921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328.

The product of its digits is 4536, while the sum is 32.

The square root of 7661921 is about 2768.0175216208. The cubic root of 7661921 is about 197.1420295571.

The spelling of 7661921 in words is "seven million, six hundred sixty-one thousand, nine hundred twenty-one".