7155551 has 4 divisors (see below), whose sum is σ = 7705992. Its totient is φ = 6605112.

The previous prime is 7155539. The next prime is 7155559. The reversal of 7155551 is 1555517.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 7155551 - 2¹⁰ = 7154527 is a prime.

It is a super-2 number, since 2×7155551² = 102403820227202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7155559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 275201 + ... + 275226.

It is an arithmetic number, because the mean of its divisors is an integer number (1926498).

Almost surely, 2^7155551 is an apocalyptic number.

7155551 is a deficient number, since it is larger than the sum of its proper divisors (550441).

7155551 is a wasteful number, since it uses less digits than its factorization.

7155551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550440.

The product of its digits is 4375, while the sum is 29.

The square root of 7155551 is about 2674.9861681885. The cubic root of 7155551 is about 192.6996949453.

The spelling of 7155551 in words is "seven million, one hundred fifty-five thousand, five hundred fifty-one".