21661465732458 has 16 divisors (see below), whose sum is σ = 43324296734496. Its totient is φ = 7220261032560.

The previous prime is 21661465732433. The next prime is 21661465732483. The reversal of 21661465732458 is 85423756416612.

It is an interprime number because it is at equal distance from previous prime (21661465732433) and next prime (21661465732483).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56679916 + ... + 57060807.

It is an arithmetic number, because the mean of its divisors is an integer number (2707768545906).

Almost surely, 2^{21661465732458} is an apocalyptic number.

21661465732458 is an abundant number, since it is smaller than the sum of its proper divisors (21662831002038).

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

21661465732458 is a wasteful number, since it uses less digits than its factorization.

21661465732458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113772469.

The product of its digits is 58060800, while the sum is 60.

The spelling of 21661465732458 in words is "twenty-one trillion, six hundred sixty-one billion, four hundred sixty-five million, seven hundred thirty-two thousand, four hundred fifty-eight".