7121651 has 4 divisors (see below), whose sum is σ = 7431312. Its totient is φ = 6811992.

The previous prime is 7121629. The next prime is 7121669. The reversal of 7121651 is 1561217.

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 7121651 - 2¹⁸ = 6859507 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 309637 = 7121651 / (7 + 1 + 2 + 1 + 6 + 5 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7124651) 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, 154796 + ... + 154841.

It is an arithmetic number, because the mean of its divisors is an integer number (1857828).

Almost surely, 2^7121651 is an apocalyptic number.

7121651 is a deficient number, since it is larger than the sum of its proper divisors (309661).

7121651 is a wasteful number, since it uses less digits than its factorization.

7121651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309660.

The product of its digits is 420, while the sum is 23.

The square root of 7121651 is about 2668.6421640977. The cubic root of 7121651 is about 192.3949029962.

Adding to 7121651 its reverse (1561217), we get a palindrome (8682868).

The spelling of 7121651 in words is "seven million, one hundred twenty-one thousand, six hundred fifty-one".