42509271981 has 16 divisors (see below), whose sum is σ = 62443867968. Its totient is φ = 25508112000.

The previous prime is 42509271943. The next prime is 42509271983. The reversal of 42509271981 is 18917290524.

It is a happy number.

It is not a de Polignac number, because 42509271981 - 2¹⁹ = 42508747693 is a prime.

It is a super-2 number, since 2×42509271981² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 42509271981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42509271983) 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, 6373696 + ... + 6380361.

It is an arithmetic number, because the mean of its divisors is an integer number (3902741748).

Almost surely, 2^42509271981 is an apocalyptic number.

It is an amenable number.

42509271981 is a deficient number, since it is larger than the sum of its proper divisors (19934595987).

42509271981 is a wasteful number, since it uses less digits than its factorization.

42509271981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12754172.

The product of its (nonzero) digits is 362880, while the sum is 48.

The spelling of 42509271981 in words is "forty-two billion, five hundred nine million, two hundred seventy-one thousand, nine hundred eighty-one".