1221057493 has 4 divisors (see below), whose sum is σ = 1222004608. Its totient is φ = 1220110380.

The previous prime is 1221057479. The next prime is 1221057527. The reversal of 1221057493 is 3947501221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221057493 is a prime.

It is a super-2 number, since 2×1221057493² = 2981962802422890098, 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 (1221057413) 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, 471621 + ... + 474202.

It is an arithmetic number, because the mean of its divisors is an integer number (305501152).

Almost surely, 2^1221057493 is an apocalyptic number.

It is an amenable number.

1221057493 is a deficient number, since it is larger than the sum of its proper divisors (947115).

1221057493 is an equidigital number, since it uses as much as digits as its factorization.

1221057493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 947114.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 1221057493 is about 34943.6330824372. The cubic root of 1221057493 is about 1068.8383739697.

The spelling of 1221057493 in words is "one billion, two hundred twenty-one million, fifty-seven thousand, four hundred ninety-three".