145421237 has 4 divisors (see below), whose sum is σ = 156607500. Its totient is φ = 134234976.

The previous prime is 145421233. The next prime is 145421251. The reversal of 145421237 is 732124541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 732124541 = 13109 ⋅55849.

It can be written as a sum of positive squares in 2 ways, for example, as 79584241 + 65836996 = 8921^2 + 8114^2 .

It is a cyclic number.

It is not a de Polignac number, because 145421237 - 2² = 145421233 is a prime.

It is a super-2 number, since 2×145421237² = 42294672341220338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145421233) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5593112 + ... + 5593137.

It is an arithmetic number, because the mean of its divisors is an integer number (39151875).

Almost surely, 2^145421237 is an apocalyptic number.

It is an amenable number.

145421237 is a deficient number, since it is larger than the sum of its proper divisors (11186263).

145421237 is a wasteful number, since it uses less digits than its factorization.

145421237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11186262.

The product of its digits is 6720, while the sum is 29.

The square root of 145421237 is about 12059.0728084708. The cubic root of 145421237 is about 525.8670323202.

Adding to 145421237 its reverse (732124541), we get a palindrome (877545778).

The spelling of 145421237 in words is "one hundred forty-five million, four hundred twenty-one thousand, two hundred thirty-seven".