1651561121 has 8 divisors (see below), whose sum is σ = 1926019200. Its totient is φ = 1415623524.

The previous prime is 1651561117. The next prime is 1651561127. The reversal of 1651561121 is 1211651561.

It is not a de Polignac number, because 1651561121 - 2² = 1651561117 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1651561127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2407181 + ... + 2407866.

It is an arithmetic number, because the mean of its divisors is an integer number (240752400).

Almost surely, 2^1651561121 is an apocalyptic number.

It is an amenable number.

1651561121 is a deficient number, since it is larger than the sum of its proper divisors (274458079).

1651561121 is an frugal number, since it uses more digits than its factorization.

1651561121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4815068 (or 4815054 counting only the distinct ones).

The product of its digits is 1800, while the sum is 29.

The square root of 1651561121 is about 40639.4035512334. The cubic root of 1651561121 is about 1182.0383043541.

The spelling of 1651561121 in words is "one billion, six hundred fifty-one million, five hundred sixty-one thousand, one hundred twenty-one".