1221572631 has 4 divisors (see below), whose sum is σ = 1628763512. Its totient is φ = 814381752.

The previous prime is 1221572623. The next prime is 1221572647. The reversal of 1221572631 is 1362751221.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1221572631 - 2³ = 1221572623 is a prime.

It is a super-2 number, since 2×1221572631² = 2984479385616524322, 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 (1221572731) 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, 203595436 + ... + 203595441.

It is an arithmetic number, because the mean of its divisors is an integer number (407190878).

Almost surely, 2^1221572631 is an apocalyptic number.

1221572631 is a deficient number, since it is larger than the sum of its proper divisors (407190881).

1221572631 is an equidigital number, since it uses as much as digits as its factorization.

1221572631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407190880.

The product of its digits is 5040, while the sum is 30.

The square root of 1221572631 is about 34951.0032903206. The cubic root of 1221572631 is about 1068.9886595090.

The spelling of 1221572631 in words is "one billion, two hundred twenty-one million, five hundred seventy-two thousand, six hundred thirty-one".