145904921 has 2 divisors, whose sum is σ = 145904922. Its totient is φ = 145904920.

The previous prime is 145904911. The next prime is 145904951. The reversal of 145904921 is 129409541.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 144120025 + 1784896 = 12005^2 + 1336^2 .

It is an emirp because it is prime and its reverse (129409541) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 145904921 - 2²⁶ = 78796057 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (145904911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72952460 + 72952461.

It is an arithmetic number, because the mean of its divisors is an integer number (72952461).

Almost surely, 2^145904921 is an apocalyptic number.

It is an amenable number.

145904921 is a deficient number, since it is larger than the sum of its proper divisors (1).

145904921 is an equidigital number, since it uses as much as digits as its factorization.

145904921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 145904921 is about 12079.1109358264. The cubic root of 145904921 is about 526.4494139908.

The spelling of 145904921 in words is "one hundred forty-five million, nine hundred four thousand, nine hundred twenty-one".