15609945 has 16 divisors (see below), whose sum is σ = 26897472. Its totient is φ = 7684800.

The previous prime is 15609943. The next prime is 15609947. The reversal of 15609945 is 54990651.

15609945 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (15609943) and next prime (15609947).

It is not a de Polignac number, because 15609945 - 2¹ = 15609943 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (15609943) 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, 39831 + ... + 40220.

It is an arithmetic number, because the mean of its divisors is an integer number (1681092).

Almost surely, 2^15609945 is an apocalyptic number.

15609945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

15609945 is a deficient number, since it is larger than the sum of its proper divisors (11287527).

15609945 is a wasteful number, since it uses less digits than its factorization.

15609945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80072.

The product of its (nonzero) digits is 48600, while the sum is 39.

The square root of 15609945 is about 3950.9422926689. The cubic root of 15609945 is about 249.9196808648.

It can be divided in two parts, 15 and 609945, that added together give a triangular number (609960 = T₁₁₀₄).

The spelling of 15609945 in words is "fifteen million, six hundred nine thousand, nine hundred forty-five".