21097271942 has 4 divisors (see below), whose sum is σ = 31645907916. Its totient is φ = 10548635970.

The previous prime is 21097271941. The next prime is 21097272011. The reversal of 21097271942 is 24917279012.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21097271893 and 21097271902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21097271941) 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 as a sum of consecutive naturals, namely, 5274317984 + ... + 5274317987.

It is an arithmetic number, because the mean of its divisors is an integer number (7911476979).

Almost surely, 2^21097271942 is an apocalyptic number.

21097271942 is a deficient number, since it is larger than the sum of its proper divisors (10548635974).

21097271942 is a wasteful number, since it uses less digits than its factorization.

21097271942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10548635973.

The product of its (nonzero) digits is 127008, while the sum is 44.

The spelling of 21097271942 in words is "twenty-one billion, ninety-seven million, two hundred seventy-one thousand, nine hundred forty-two".