7121725 has 24 divisors (see below), whose sum is σ = 10077480. Its totient is φ = 4945920.

The previous prime is 7121717. The next prime is 7121731. The reversal of 7121725 is 5271217.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 1153476 + 5968249 = 1074^2 + 2443^2 .

It is not a de Polignac number, because 7121725 - 2³ = 7121717 is a prime.

It is a super-4 number, since 4×7121725⁴ (a number of 29 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

7121725 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 7121725.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4881 + ... + 6169.

It is an arithmetic number, because the mean of its divisors is an integer number (419895).

Almost surely, 2^7121725 is an apocalyptic number.

It is an amenable number.

7121725 is a deficient number, since it is larger than the sum of its proper divisors (2955755).

7121725 is a wasteful number, since it uses less digits than its factorization.

7121725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1329 (or 1324 counting only the distinct ones).

The product of its digits is 980, while the sum is 25.

The square root of 7121725 is about 2668.6560287905. The cubic root of 7121725 is about 192.3955693760.

The spelling of 7121725 in words is "seven million, one hundred twenty-one thousand, seven hundred twenty-five".