155661040 has 20 divisors (see below), whose sum is σ = 361912104. Its totient is φ = 62264384.

The previous prime is 155661029. The next prime is 155661043. The reversal of 155661040 is 40166551.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155661043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 972802 + ... + 972961.

Almost surely, 2^155661040 is an apocalyptic number.

155661040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

155661040 is an abundant number, since it is smaller than the sum of its proper divisors (206251064).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

155661040 is a wasteful number, since it uses less digits than its factorization.

155661040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1945776 (or 1945770 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 155661040 is about 12476.4193581332. The cubic root of 155661040 is about 537.9310866528.

The spelling of 155661040 in words is "one hundred fifty-five million, six hundred sixty-one thousand, forty".