1451021221 has 4 divisors (see below), whose sum is σ = 1562638252. Its totient is φ = 1339404192.

The previous prime is 1451021191. The next prime is 1451021261. The reversal of 1451021221 is 1221201541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1221201541 = 7 ⋅174457363.

It can be written as a sum of positive squares in 2 ways, for example, as 119793025 + 1331228196 = 10945^2 + 36486^2 .

It is a cyclic number.

It is not a de Polignac number, because 1451021221 - 2¹⁵ = 1450988453 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 (1451021261) 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, 55808496 + ... + 55808521.

It is an arithmetic number, because the mean of its divisors is an integer number (390659563).

Almost surely, 2^1451021221 is an apocalyptic number.

It is an amenable number.

1451021221 is a deficient number, since it is larger than the sum of its proper divisors (111617031).

1451021221 is a wasteful number, since it uses less digits than its factorization.

1451021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111617030.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 1451021221 is about 38092.2724578096. The cubic root of 1451021221 is about 1132.1168508963.

Adding to 1451021221 its reverse (1221201541), we get a palindrome (2672222762).

The spelling of 1451021221 in words is "one billion, four hundred fifty-one million, twenty-one thousand, two hundred twenty-one".