161537638 has 32 divisors (see below), whose sum is σ = 264679488. Its totient is φ = 73651200.

The previous prime is 161537611. The next prime is 161537641. The reversal of 161537638 is 836735161.

It is a happy number.

161537638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a fibodiv number, since the Fibonacci-like sequence with seeds 1615 and 37638 contains 161537638 itself.

It is a self number, because there is not a number n which added to its sum of digits gives 161537638.

It is a congruent number.

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, 146706 + ... + 147802.

It is an arithmetic number, because the mean of its divisors is an integer number (8271234).

Almost surely, 2^161537638 is an apocalyptic number.

161537638 is a deficient number, since it is larger than the sum of its proper divisors (103141850).

161537638 is a wasteful number, since it uses less digits than its factorization.

161537638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248.

The product of its digits is 90720, while the sum is 40.

The square root of 161537638 is about 12709.7457881737. The cubic root of 161537638 is about 544.6170617479.

The spelling of 161537638 in words is "one hundred sixty-one million, five hundred thirty-seven thousand, six hundred thirty-eight".