155661400 has 24 divisors (see below), whose sum is σ = 361913220. Its totient is φ = 62264480.

The previous prime is 155661377. The next prime is 155661403. The reversal of 155661400 is 4166551.

155661400 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155661403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 388954 + ... + 389353.

Almost surely, 2^155661400 is an apocalyptic number.

155661400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

155661400 is an abundant number, since it is smaller than the sum of its proper divisors (206251820).

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

155661400 is a wasteful number, since it uses less digits than its factorization.

155661400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778323 (or 778314 counting only the distinct ones).

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

The square root of 155661400 is about 12476.4337853411. The cubic root of 155661400 is about 537.9315013466.

The spelling of 155661400 in words is "one hundred fifty-five million, six hundred sixty-one thousand, four hundred".