155399820 has 48 divisors (see below), whose sum is σ = 439621728. Its totient is φ = 41011200.

The previous prime is 155399789. The next prime is 155399833. The reversal of 155399820 is 28993551.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

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, 7531 + ... + 19170.

It is an arithmetic number, because the mean of its divisors is an integer number (9158786).

Almost surely, 2^155399820 is an apocalyptic number.

155399820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

155399820 is an abundant number, since it is smaller than the sum of its proper divisors (284221908).

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

155399820 is a wasteful number, since it uses less digits than its factorization.

155399820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26810 (or 26808 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 42.

The square root of 155399820 is about 12465.9464141316. The cubic root of 155399820 is about 537.6300114561.

The spelling of 155399820 in words is "one hundred fifty-five million, three hundred ninety-nine thousand, eight hundred twenty".