7121645 has 8 divisors (see below), whose sum is σ = 8584056. Its totient is φ = 5671936.

The previous prime is 7121629. The next prime is 7121669. The reversal of 7121645 is 5461217.

It can be written as a sum of positive squares in 4 ways, for example, as 252004 + 6869641 = 502^2 + 2621^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7121645 - 2⁴ = 7121629 is a prime.

It is a super-3 number, since 3×7121645³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1892 + ... + 4221.

It is an arithmetic number, because the mean of its divisors is an integer number (1073007).

Almost surely, 2^7121645 is an apocalyptic number.

It is an amenable number.

7121645 is a deficient number, since it is larger than the sum of its proper divisors (1462411).

7121645 is a wasteful number, since it uses less digits than its factorization.

7121645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6351.

The product of its digits is 1680, while the sum is 26.

The square root of 7121645 is about 2668.6410399302. The cubic root of 7121645 is about 192.3948489652.

The spelling of 7121645 in words is "seven million, one hundred twenty-one thousand, six hundred forty-five".