7721961 has 32 divisors (see below), whose sum is σ = 12378240. Its totient is φ = 4230144.

The previous prime is 7721953. The next prime is 7721963. The reversal of 7721961 is 1691277.

It is not a de Polignac number, because 7721961 - 2³ = 7721953 is a prime.

7721961 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7721963) 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, 12291 + ... + 12903.

It is an arithmetic number, because the mean of its divisors is an integer number (386820).

Almost surely, 2^7721961 is an apocalyptic number.

It is an amenable number.

7721961 is a deficient number, since it is larger than the sum of its proper divisors (4656279).

7721961 is a wasteful number, since it uses less digits than its factorization.

7721961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 665.

The product of its digits is 5292, while the sum is 33.

The square root of 7721961 is about 2778.8416651547. The cubic root of 7721961 is about 197.6556354811.

The spelling of 7721961 in words is "seven million, seven hundred twenty-one thousand, nine hundred sixty-one".