1661572403 has 2 divisors, whose sum is σ = 1661572404. Its totient is φ = 1661572402.

The previous prime is 1661572397. The next prime is 1661572421. The reversal of 1661572403 is 3042751661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1661572403 - 2¹⁴ = 1661556019 is a prime.

It is a super-2 number, since 2×1661572403² = 5521645700822388818, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1661572483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830786201 + 830786202.

It is an arithmetic number, because the mean of its divisors is an integer number (830786202).

Almost surely, 2^1661572403 is an apocalyptic number.

1661572403 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661572403 is an equidigital number, since it uses as much as digits as its factorization.

1661572403 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 1661572403 is about 40762.3895644012. The cubic root of 1661572403 is about 1184.4218851567.

The spelling of 1661572403 in words is "one billion, six hundred sixty-one million, five hundred seventy-two thousand, four hundred three".