1625640549 has 16 divisors (see below), whose sum is σ = 2335002432. Its totient is φ = 1000073088.

The previous prime is 1625640509. The next prime is 1625640553. The reversal of 1625640549 is 9450465261.

It is not a de Polignac number, because 1625640549 - 2⁷ = 1625640421 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1625640549.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1625640509) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 188322 + ... + 196764.

It is an arithmetic number, because the mean of its divisors is an integer number (145937652).

Almost surely, 2^1625640549 is an apocalyptic number.

It is an amenable number.

1625640549 is a deficient number, since it is larger than the sum of its proper divisors (709361883).

1625640549 is a wasteful number, since it uses less digits than its factorization.

1625640549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13396.

The product of its (nonzero) digits is 259200, while the sum is 42.

The square root of 1625640549 is about 40319.2329912165. The cubic root of 1625640549 is about 1175.8217999862.

The spelling of 1625640549 in words is "one billion, six hundred twenty-five million, six hundred forty thousand, five hundred forty-nine".