1645125601 has 8 divisors (see below), whose sum is σ = 1944976320. Its totient is φ = 1361483088.

The previous prime is 1645125551. The next prime is 1645125689. The reversal of 1645125601 is 1065215461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1645125601 - 2¹⁹ = 1644601313 is a prime.

It is a super-2 number, since 2×1645125601² = 5412876486131222402, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1645125101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4051831 + ... + 4052236.

It is an arithmetic number, because the mean of its divisors is an integer number (243122040).

Almost surely, 2^1645125601 is an apocalyptic number.

It is an amenable number.

1645125601 is a deficient number, since it is larger than the sum of its proper divisors (299850719).

1645125601 is an equidigital number, since it uses as much as digits as its factorization.

1645125601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8104103.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 1645125601 is about 40560.1479410517. The cubic root of 1645125601 is about 1180.5009844838.

The spelling of 1645125601 in words is "one billion, six hundred forty-five million, one hundred twenty-five thousand, six hundred one".