1645397138 has 32 divisors (see below), whose sum is σ = 3210900480. Its totient is φ = 613190160.

The previous prime is 1645397119. The next prime is 1645397147. The reversal of 1645397138 is 8317935461.

It is a happy number.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 1645397092 and 1645397101.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 228728 + ... + 235811.

It is an arithmetic number, because the mean of its divisors is an integer number (100340640).

Almost surely, 2^1645397138 is an apocalyptic number.

1645397138 is a deficient number, since it is larger than the sum of its proper divisors (1565503342).

1645397138 is a wasteful number, since it uses less digits than its factorization.

1645397138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464582.

The product of its digits is 544320, while the sum is 47.

The square root of 1645397138 is about 40563.4951403352. The cubic root of 1645397138 is about 1180.5659302973.

The spelling of 1645397138 in words is "one billion, six hundred forty-five million, three hundred ninety-seven thousand, one hundred thirty-eight".