131221040 has 20 divisors (see below), whose sum is σ = 305089104. Its totient is φ = 52488384.

The previous prime is 131221037. The next prime is 131221061. The reversal of 131221040 is 40122131.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×131221040² = 34437922677363200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 820052 + ... + 820211.

Almost surely, 2^131221040 is an apocalyptic number.

131221040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

131221040 is an abundant number, since it is smaller than the sum of its proper divisors (173868064).

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

131221040 is a wasteful number, since it uses less digits than its factorization.

131221040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1640276 (or 1640270 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 131221040 is about 11455.1752496415. The cubic root of 131221040 is about 508.1607980853.

Adding to 131221040 its reverse (40122131), we get a palindrome (171343171).

The spelling of 131221040 in words is "one hundred thirty-one million, two hundred twenty-one thousand, forty".