1971148421 has 16 divisors (see below), whose sum is σ = 2178318528. Its totient is φ = 1768752000.

The previous prime is 1971148379. The next prime is 1971148433. The reversal of 1971148421 is 1248411791.

It is a cyclic number.

It is not a de Polignac number, because 1971148421 - 2¹⁰ = 1971147397 is a prime.

It is a super-2 number, since 2×1971148421² = 7770852195221586482, which 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 (1971148441) 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, 382961 + ... + 388073.

It is an arithmetic number, because the mean of its divisors is an integer number (136144908).

Almost surely, 2^1971148421 is an apocalyptic number.

1971148421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1971148421 is a deficient number, since it is larger than the sum of its proper divisors (207170107).

1971148421 is a wasteful number, since it uses less digits than its factorization.

1971148421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5572.

The product of its digits is 16128, while the sum is 38.

The square root of 1971148421 is about 44397.6172896699. The cubic root of 1971148421 is about 1253.8332295452.

The spelling of 1971148421 in words is "one billion, nine hundred seventy-one million, one hundred forty-eight thousand, four hundred twenty-one".