145309421 has 8 divisors (see below), whose sum is σ = 154207800. Its totient is φ = 136450048.

The previous prime is 145309393. The next prime is 145309457. The reversal of 145309421 is 124903541.

It can be written as a sum of positive squares in 4 ways, for example, as 8185321 + 137124100 = 2861^2 + 11710^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 145309421 - 2⁶ = 145309357 is a prime.

It is a super-2 number, since 2×145309421² = 42229655662710482, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145309481) 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, 1886 + ... + 17151.

It is an arithmetic number, because the mean of its divisors is an integer number (19275975).

Almost surely, 2^145309421 is an apocalyptic number.

It is an amenable number.

145309421 is a deficient number, since it is larger than the sum of its proper divisors (8898379).

145309421 is a wasteful number, since it uses less digits than its factorization.

145309421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19503.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 145309421 is about 12054.4357395940. The cubic root of 145309421 is about 525.7322160983.

The spelling of 145309421 in words is "one hundred forty-five million, three hundred nine thousand, four hundred twenty-one".