1025721611 has 4 divisors (see below), whose sum is σ = 1025790792. Its totient is φ = 1025652432.

The previous prime is 1025721607. The next prime is 1025721623. The reversal of 1025721611 is 1161275201.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1161275201 = 47 ⋅24707983.

It is a cyclic number.

It is not a de Polignac number, because 1025721611 - 2² = 1025721607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1025721601) 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, 2306 + ... + 45351.

It is an arithmetic number, because the mean of its divisors is an integer number (256447698).

Almost surely, 2^1025721611 is an apocalyptic number.

1025721611 is a deficient number, since it is larger than the sum of its proper divisors (69181).

1025721611 is an equidigital number, since it uses as much as digits as its factorization.

1025721611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69180.

The product of its (nonzero) digits is 840, while the sum is 26.

The square root of 1025721611 is about 32026.8888748189. Note that the first 4 decimals coincide. The cubic root of 1025721611 is about 1008.5013918608.

Adding to 1025721611 its reverse (1161275201), we get a palindrome (2186996812).

The spelling of 1025721611 in words is "one billion, twenty-five million, seven hundred twenty-one thousand, six hundred eleven".