7721985 has 16 divisors (see below), whose sum is σ = 12390336. Its totient is φ = 4106688.

The previous prime is 7721977. The next prime is 7721993. The reversal of 7721985 is 5891277.

It is an interprime number because it is at equal distance from previous prime (7721977) and next prime (7721993).

It is not a de Polignac number, because 7721985 - 2³ = 7721977 is a prime.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8367 + ... + 9243.

It is an arithmetic number, because the mean of its divisors is an integer number (774396).

Almost surely, 2^7721985 is an apocalyptic number.

It is an amenable number.

7721985 is a deficient number, since it is larger than the sum of its proper divisors (4668351).

7721985 is a wasteful number, since it uses less digits than its factorization.

7721985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1472.

The product of its digits is 35280, while the sum is 39.

The square root of 7721985 is about 2778.8459834975. The cubic root of 7721985 is about 197.6558402534.

The spelling of 7721985 in words is "seven million, seven hundred twenty-one thousand, nine hundred eighty-five".