1025206421 has 4 divisors (see below), whose sum is σ = 1025333100. Its totient is φ = 1025079744.

The previous prime is 1025206411. The next prime is 1025206423. The reversal of 1025206421 is 1246025201.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1246025201 = 11161 ⋅111641.

It can be written as a sum of positive squares in 2 ways, for example, as 659976100 + 365230321 = 25690^2 + 19111^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1025206421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1025206423) 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, 50306 + ... + 67683.

It is an arithmetic number, because the mean of its divisors is an integer number (256333275).

Almost surely, 2^1025206421 is an apocalyptic number.

It is an amenable number.

1025206421 is a deficient number, since it is larger than the sum of its proper divisors (126679).

1025206421 is an equidigital number, since it uses as much as digits as its factorization.

1025206421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126678.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 1025206421 is about 32018.8447792858. The cubic root of 1025206421 is about 1008.3325166550.

The spelling of 1025206421 in words is "one billion, twenty-five million, two hundred six thousand, four hundred twenty-one".