21571497290 has 32 divisors (see below), whose sum is σ = 44833146624. Its totient is φ = 7319692800.

The previous prime is 21571497289. The next prime is 21571497293. The reversal of 21571497290 is 9279417512.

It is not an unprimeable number, because it can be changed into a prime (21571497293) 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, 1581686 + ... + 1595265.

It is an arithmetic number, because the mean of its divisors is an integer number (1401035832).

Almost surely, 2^21571497290 is an apocalyptic number.

21571497290 is an abundant number, since it is smaller than the sum of its proper divisors (23261649334).

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

21571497290 is a wasteful number, since it uses less digits than its factorization.

21571497290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3177062.

The product of its (nonzero) digits is 317520, while the sum is 47.

The spelling of 21571497290 in words is "twenty-one billion, five hundred seventy-one million, four hundred ninety-seven thousand, two hundred ninety".