1292127421 has 4 divisors (see below), whose sum is σ = 1391521852. Its totient is φ = 1192732992.

The previous prime is 1292127409. The next prime is 1292127491. The reversal of 1292127421 is 1247212921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1247212921 = 421 ⋅2962501.

It can be written as a sum of positive squares in 2 ways, for example, as 880605625 + 411521796 = 29675^2 + 20286^2 .

It is a cyclic number.

It is not a de Polignac number, because 1292127421 - 2¹³ = 1292119229 is a prime.

It is a super-2 number, since 2×1292127421² = 3339186544200222482, 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 (1292127491) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49697196 + ... + 49697221.

It is an arithmetic number, because the mean of its divisors is an integer number (347880463).

Almost surely, 2^1292127421 is an apocalyptic number.

It is an amenable number.

1292127421 is a deficient number, since it is larger than the sum of its proper divisors (99394431).

1292127421 is an equidigital number, since it uses as much as digits as its factorization.

1292127421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99394430.

The product of its digits is 4032, while the sum is 31.

The square root of 1292127421 is about 35946.1739410469. The cubic root of 1292127421 is about 1089.1853242580.

The spelling of 1292127421 in words is "one billion, two hundred ninety-two million, one hundred twenty-seven thousand, four hundred twenty-one".