155778490 has 16 divisors (see below), whose sum is σ = 320458752. Its totient is φ = 53409744.

The previous prime is 155778487. The next prime is 155778499. The reversal of 155778490 is 94877551.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 155778490.

It is not an unprimeable number, because it can be changed into a prime (155778499) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1112634 + ... + 1112773.

It is an arithmetic number, because the mean of its divisors is an integer number (20028672).

Almost surely, 2^155778490 is an apocalyptic number.

155778490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

155778490 is an abundant number, since it is smaller than the sum of its proper divisors (164680262).

155778490 is a wasteful number, since it uses less digits than its factorization.

155778490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2225421.

The product of its (nonzero) digits is 352800, while the sum is 46.

The square root of 155778490 is about 12481.1253499033. The cubic root of 155778490 is about 538.0663466221.

The spelling of 155778490 in words is "one hundred fifty-five million, seven hundred seventy-eight thousand, four hundred ninety".