21194598981 has 8 divisors (see below), whose sum is σ = 28269892480. Its totient is φ = 14124519072.

The previous prime is 21194598973. The next prime is 21194598983. The reversal of 21194598981 is 18989549112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21194598981 - 2³ = 21194598973 is a prime.

It is a super-2 number, since 2×21194598981² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21194598983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1293901 + ... + 1310178.

It is an arithmetic number, because the mean of its divisors is an integer number (3533736560).

Almost surely, 2^21194598981 is an apocalyptic number.

It is an amenable number.

21194598981 is a deficient number, since it is larger than the sum of its proper divisors (7075293499).

21194598981 is a wasteful number, since it uses less digits than its factorization.

21194598981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2606795.

The product of its digits is 1866240, while the sum is 57.

The spelling of 21194598981 in words is "twenty-one billion, one hundred ninety-four million, five hundred ninety-eight thousand, nine hundred eighty-one".