821263542 has 24 divisors (see below), whose sum is σ = 1805423928. Its totient is φ = 248867520.

The previous prime is 821263517. The next prime is 821263549. The reversal of 821263542 is 245362128.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821263549) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 564883 + ... + 566334.

It is an arithmetic number, because the mean of its divisors is an integer number (75225997).

Almost surely, 2^821263542 is an apocalyptic number.

821263542 is an abundant number, since it is smaller than the sum of its proper divisors (984160386).

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

821263542 is a wasteful number, since it uses less digits than its factorization.

821263542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1131244 (or 1131233 counting only the distinct ones).

The product of its digits is 23040, while the sum is 33.

The square root of 821263542 is about 28657.6960343989. The cubic root of 821263542 is about 936.4706728605.

The spelling of 821263542 in words is "eight hundred twenty-one million, two hundred sixty-three thousand, five hundred forty-two".