145821990 has 32 divisors (see below), whose sum is σ = 350334720. Its totient is φ = 38845664.

The previous prime is 145821989. The next prime is 145822003. The reversal of 145821990 is 99128541.

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, 37351 + ... + 41069.

It is an arithmetic number, because the mean of its divisors is an integer number (10947960).

Almost surely, 2^145821990 is an apocalyptic number.

145821990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

145821990 is an abundant number, since it is smaller than the sum of its proper divisors (204512730).

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

145821990 is a wasteful number, since it uses less digits than its factorization.

145821990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5036.

The product of its (nonzero) digits is 25920, while the sum is 39.

The square root of 145821990 is about 12075.6776207383. The cubic root of 145821990 is about 526.3496521037.

The spelling of 145821990 in words is "one hundred forty-five million, eight hundred twenty-one thousand, nine hundred ninety".