450721638 has 32 divisors (see below), whose sum is σ = 1002626400. Its totient is φ = 150087168.

The previous prime is 450721633. The next prime is 450721669. The reversal of 450721638 is 836127054.

It is a super-2 number, since 2×450721638² = 406299989922806088, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (450721633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57270 + ... + 64662.

It is an arithmetic number, because the mean of its divisors is an integer number (31332075).

Almost surely, 2^450721638 is an apocalyptic number.

450721638 is an abundant number, since it is smaller than the sum of its proper divisors (551904762).

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

450721638 is a wasteful number, since it uses less digits than its factorization.

450721638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8533 (or 8527 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 450721638 is about 21230.2057926908. The cubic root of 450721638 is about 766.7188417758.

The spelling of 450721638 in words is "four hundred fifty million, seven hundred twenty-one thousand, six hundred thirty-eight".