19745945 has 16 divisors (see below), whose sum is σ = 24319440. Its totient is φ = 15385344.

The previous prime is 19745917. The next prime is 19745953. The reversal of 19745945 is 54954791.

It can be written as a sum of positive squares in 8 ways, for example, as 2968729 + 16777216 = 1723^2 + 4096^2 .

It is a cyclic number.

It is not a de Polignac number, because 19745945 - 2⁸ = 19745689 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19745896 and 19745905.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71147 + ... + 71423.

It is an arithmetic number, because the mean of its divisors is an integer number (1519965).

Almost surely, 2^19745945 is an apocalyptic number.

It is an amenable number.

19745945 is a deficient number, since it is larger than the sum of its proper divisors (4573495).

19745945 is a wasteful number, since it uses less digits than its factorization.

19745945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 604.

The product of its digits is 226800, while the sum is 44.

The square root of 19745945 is about 4443.6409620940. The cubic root of 19745945 is about 270.2875080974.

The spelling of 19745945 in words is "nineteen million, seven hundred forty-five thousand, nine hundred forty-five".