395213021 has 16 divisors (see below), whose sum is σ = 470256384. Its totient is φ = 325067904.

The previous prime is 395212973. The next prime is 395213033. The reversal of 395213021 is 120312593.

395213021 = 289² + 290² + ... + 1065².

It is not a de Polignac number, because 395213021 - 2¹⁸ = 394950877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (395213041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8456 + ... + 29358.

It is an arithmetic number, because the mean of its divisors is an integer number (29391024).

Almost surely, 2^395213021 is an apocalyptic number.

It is an amenable number.

395213021 is a deficient number, since it is larger than the sum of its proper divisors (75043363).

395213021 is a wasteful number, since it uses less digits than its factorization.

395213021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21020.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 395213021 is about 19879.9653168712. The cubic root of 395213021 is about 733.8552658814.

The spelling of 395213021 in words is "three hundred ninety-five million, two hundred thirteen thousand, twenty-one".